Noodles have a very long history in China and, as such, achieving any accurate history of the origin of la mian is wrought with difficulty. Recorded histories of noodles in China date back over 1900 years to the Eastern Han Dynasty. Though it is generally understood that not until the Ming Dynasty did the superior skills of noodle makers achieve the art of the hand-pulled noodle, or 拉面.
The modern Lanzhou variety of the hand-pulled noodles and their distinctive broth have developed as a collective food habit of the minority Hui Muslim people in north-western China.
A young Hui man who sold the hot soup noodles topped with beef cubes on the streets of Lanzhou during the Qing Dynasty is credited with developing the dish in its current form. Mao Baozi's (马包子, 1870-1955) noodles attracted such fame for their taste that they were named "Ma Baozi beef noodles". The traditional characteristics of Ma Baozi Beef Noodles are said to be "1 clear, 2 white, 3 red, 4 green, 5 yellow" (一清、二白、三红、四绿、五黄) to signify respectively clear soup, white radish, red chili oil, green coriander and yellow noodles. (Using an alkali imparts a yellowish tint to the noodles, which use no egg.)
In 1919 Ma Baozi opened his first restaurant in the city, leading to the eventual growth of thousands of beef noodle restaurants in Lanzhou. Outside of Lanzhou, such noodle shops carry the title of 兰州正宗拉面 (authentic Lanzhou hand-pulled noodles), while in the city itself they generally just mention beef noodles (牛肉面).
While la mian shops in Qingdao also display similar signage that indicates authentic Lanzhou pulled noodles, the Hui nationality families who run them frequently do not originate from Gansu province or its capital Lanzhou, but from neighbouring Qinghai. Interestingly too, there has been a strong tendency in Qingdao to incorporate the popular medical herb, angelica – known as 当归 or dang gui in Chinese – into the la mian broth for apparent health reasons. This has become an important point of conjecture amongst the la mian community in the coastal city. Check the Recipe section for more information on this matter.
4,000-Year-Old Noodles Found in China: http://news.nationalgeographic.com/news/2005/10/1012_051012_chinese_noodles.html