Kevin Pan, From China
It was derived from the late Qing dynasty when Russia annexed large parts of territories in Qing's northeast, during the process through contact with the Russians, China's northeasterners thought they are rude and rough, and also as Russians are mostly of Caucasians, whose bodies tend to be pretty hairy. As a combination of these two factors, the word “Lao Mao Zi” is a derogatory stereotype about them.
Shiyue Mao, lives in China
In brief, "Lao mao tzu" or "Lao mao zi" (老毛子) is an idiom typically used in the northeast region of China, where the territory borders on Russia. This phrase is used to call Russian with disfavor and contempt.
It was originated from the late period of Qing Dynasty, about more than 100 years ago, when Russia invaded China and occupied a great number of lands in the northeast region of China. Due to the brutal acts and behaviour, local dwellers created such a phrase as "Lao mao zi" to describe Russians by their shape and exterior.
BTW, Russians are not the only group of people who are named with contempt by Chinese, others like Korean (棒子), Indian (阿三), Japanese (鬼子), etc. are all called by a specially contempt name. I do not agree such rude behavior and I hope it would be rare in future. After all, all races are equally living in the world.
简单的说，“Lao mao tzu”或"Lao mao zi" ( 老毛子 ) 是一个中国东北地区典型俗语，该地区的领土与俄罗斯接壤，这个短语用来称呼俄罗斯人，指其不受欢迎和蔑视的意思。
此外，俄罗斯人并不是唯一被中国人轻蔑的群体，其他人，如韩国人( 棒子 )、印度人( 阿三 )、日本人( 鬼子 ) 等，都是特别轻蔑的称呼，我不同意这种粗鲁的行为，我希望将来这种行为会更少见，毕竟，世界上所有的种族都是平等的。
Robinson Law, don't really like any religion
The best answer is shown below:
Tsarist Russia was originated from the Duchy of Moscow. Through continuous expansion, it has become a trans-Eurasian Empire by the time it reached Peter I and Catherine.
Initially a Chinese territory throughout the Yuan Dynasty, the Russians appropriated the Lingbei and Liaoyang provinces and large tracts of land for themselves during this time. It has also gradually begun to cause territorial disputes and regional conflicts unilaterally with China's Qing Dynasty, riding on the latter's national decline.
The Czar of Russia took the opportunity to move further south, forced the Qing government to cede further, the area to the north of Heilongjiang Stanovoy (originally Chinese Manchu), a vast territory in which Mongolians and other ethnic minorities lived for generations.
It has also infiltrated China's northeast hinterland, mad grabbing all possible interests. In the process of constant invasion, the Tsarist Russians brutally murdered people across lands, including cases such as Sixty-Four Villages East of the Blagoveshchensk River and the terminations of local ethnic Hans.
Russia's barbaric aggression aroused indignation of the Chinese people, the word"Lao Maozi"was created in such a background, by combining the Russian people's physical characteristics and temperaments generated.
Steven Lee (李揚靈), lived in China
People in Eastern European countries, typically used to belong to the Soviet Union, are all called "Maozi", not just the Russians.
That is based on a stereotype that eastern Europeans are very hairy and rude (brute).
So the Russians, the Belarus, the Ukranians are called "Lao Maozi" (老毛子) or "White Maozi" (白毛子) cause they have fair skin, while the Azerbaijans and the Turks are called "Black Maozi" (黑毛子) because of the ralatively darker skin, in addition, those ostentatious Eastern Europeans are call Big Maozi (大毛子).
这基于东欧人非常多毛和粗鲁( 野蛮 ) 的刻板印象。
因此，俄罗斯人、白俄罗斯人、乌克兰人被称为“ 老毛子 ”( Lao Maozi )或“白毛子”( White Maozi )，因为他们皮肤白皙，阿塞拜疆人和突厥人因皮肤相对较黑而被称为“黑毛子”( Black Maozi )，此外，那些招摇的东欧人被称为“大毛子”(Big Maozi)。
Yi Lu, born and educated in China, working to become a Chinese academic.
I just checked Chinese online encyclopedia and translate the contents below:
It was a calling with scorn, originated from Northeast China more than 100 years ago. At that time China was in Qing Dynasty and was not industralized. Russia was strong and invaded China and encroached our land. Northeast people were close to the border and suffered. They hated the invaders and call them “Lao Mao zi”. Literally “Mao” means hair, so I guess that is because Russians have longer hair compared with us.
But time has changed and the emotion in this word fades out. I didn’t know the history either until I checked its origins online. I think most Chinese don’t know that. It becomes just a casual nickname for Russians. So I hope you and your classmates get along well :)
Huseyin Esin Altun, Entrepreneur, Business Consultant, Teacher in Shanghai,China
老毛子 (lao mao zi) basically means ‘hairy’ and the term is believed to be originated in the northern part of China called Dongbei where there are many Russians settled from the old times on. Because Chinese people are so fond of calling foreigners weird names (sometimes quite on point tho) in order to label or just call them and even Russians have hairier bodies than Chinese, they are called ‘老毛子’.
mao（毛） is a Chinese character which means hairy .That’s just the straight feeling of the Russion appearance.
UNFORTUNATELY it is invited by Chinese as a pejorative appellation for the invasion of Tsar in Qing dynasty.
BUT by now the pejorative meaning of the word is almost disappeared and replaced with the admiring of the tough Russia military tech and doughty lifestyle.
As a Chinese, I'm not sure what does “MaoZi” mean in the past. But currently it's not a bad name. “Lao”actually shows a kind of close relationship, just like when Chinese call foreigners “Lao Wai” it actually shows friendly.
By the way, most of Chinese don't call Russian “LaoMaoZi” but call them “ELuoSiRen” (Russian).
顺便说一句，大多数中国人不叫俄罗斯人“老毛子”，而是叫他们“ ELuoSiRen”( 俄罗斯人)。
Thomas, lived in China
i Just want to say that this description tends to be Derogatory sense...We also call them "mao tzu" and their nation "the fighter nation".they come from the the "cold" world and are always furry."mao"(毛) means their furry and it's the key word."tzu" can be used as noun suffix in chinese culture.
我只想说，这种描述往往是贬义的。。。我们也称他们为"毛子"（mao tzu），称他们的民族是" 战斗民族"， 他们来自" 寒冷"的世界，毛发茂盛， "mao"(毛) 是指毛茸茸的，这是关键词， " tzu"（子）在中国文化中可以用作名词后缀。
The word for hat, 帽子 màozi, also comes to mind. In the West we're also familiar with the stereotype of Russians wearing big fur hats with flaps that fold down.
Peson Wang, API Sales
In this word, the key is “mao tzu”, in fact, we call it “mao zi” the mean is the guy who have many chaeta, you know chineses usually don’t thrive for that, and Russians almost have this feature.
And the first word “lao” just a usual adjectives word for person.
在这个词中，关键词是“mao tzu”，实际上，我们称它为“Mao zi”，意思是有很多毛发的人，你知道中国人通常毛发不茂盛，而俄罗斯人却有这个特点。
The nick name of the famous director Zhang Yimou is Lao Mou Tzu. so you see it is not that bad. Lao (literally means old) means 'sharp', 'not simple' or 'experienced'. In the north, when you are 40 years old or above, it is common to be called Lao xxx where xxx is you family name. It doesn't really mean you are old. Mao (hairy) is to describe Russians. Tzu is just a common word to complete the nick name in the north. For example, son is often called 儿子 (er tzu) instead of 儿 (er). wife is called 妻子 (qi tzu) instead of 妻 (qi).
著名导演张艺谋的昵称是“老谋子”，所以你看，也没那么糟糕。“老”(字面意思是“old ”)的意思是“犀利”、“不简单”或“有经验”，在北方，当你40岁或40岁以上时，人们通常称你为“老XXX”，其中xxx是你的姓氏，这并不意味着你真的老了，“Mao”毛是用来形容俄罗斯人的，在北方，“ Tzu”只是一个普通的词用来结束昵称。例如，儿子通常被称为“儿子( Er tzu) ”而不是“儿”(“er”)，妻子则被称为“妻子”( qi tzu)，而不是“妻”(“qi”)。
Lao mao tuz "老毛子" is a old-fashioned way to call Russians
The more popular way to call them is "nation of fight" 战斗民族
更流行的称呼是“战斗民族”（"nation of fight"）。
Galano Han, interests
Because the Cossacks were sent to the outer Amur river area as the early Russian settlers. Normally these soldiers had long mustaches and beards, with leather caps.
Duan Mengyan, college student about ad
毛 mao means fine hair.I think there are two reasons. one is Russians have much whiskers and they always wear fur coat which because winter is cold and long .besides they are strong enough and without fear .They can drink vodka with bear .So chinese also call them mao xiong （毛熊）or zhan dou min zu（战斗民族）(means they are forceful) . It is like a joke .
毛的意思是“ 多毛的”。我认为有两个原因。一个是俄罗斯人长胡子，他们总是穿毛皮大衣，因为冬天又冷又长。此外，他们很强壮，无所畏惧，他们可以和熊一起喝伏特加，所以中国人也叫他们毛熊或战斗民族。( 意思是说他们很有力量)，这是一句玩笑话。