本文詳盡地論述了北方遊牧民族賴以生存的基礎食物乳製品，透過其品種的發生、發展、進步，說明乳製品在北方人群經濟生活中的位置。遊牧人群之所以能夠遊牧，做遠距離的移動，與乳製品產生有密切的關聯。酸乳、乳酪都是發酵技術的產物，人們利用不同的季節製作它們，使之成爲主要食物，用於維持生計。作爲食品的飲用，實際上是文化的重要組成部分，乳品喜好或被拒絕都會貫穿著一種文化理念。圍繞著乳品產生諸多習俗，代表了不同的財富程度、社會地位。黑色的馬乳酒是蒙元上層貴族的高貴飲品，普通的乾酪則是下層百姓最基本食物。醍醐百煉成精，是將乳品製作技術精細化的程度發揮到了極致。這裏所討論到的蒸餾酒技術或許是北方民族的另一重要貢獻。雖然，乳製品長期以來是北方遊牧民族的基礎食物，經北朝至隋唐達到一個高潮，再經蒙古人的推介對中國社會曾產生深刻的影響。然而，遊牧人群喜好乳品的經驗，並沒有使中國人產生大規模食用的習俗，進而推及整個東亞人群都沒有食用乳製品習慣。這一結果使人們深感困惑並尋求多角度的解釋，當我們徹底地從技術的角度，瞭解這些乳製品原料來源、製造方法和與之相配套的生計模式，多多少少會對乳品的流行或不流行產生一些理解。任何人群基礎食品的形成都是在生存壓力下最明智、最經濟的選擇結果，一旦獲得技術上的突破，任何食品都有迅速擴散到其他人群的可能。工業化模式的生成，現代社會便捷的交通更爲這種可能提供了先決條件。

This article presents a detailed account of one of the northern nomads' basic foods-milk products. By examining the first appearance of different varieties of milk products, their development and progress, it explains the position that milk products have in economic life of the northern peoples. The fact that nomadic peoples are able to move about in search of pasture and undertake long-distance migrations has a close connection with the development of milk products. Sour milk (yogurt) and cheese are both the products of a fermentation technology. People make use of the different seasons to manufacture them, making them become a staple food to maintain the lives. The ingestion of liquid foods is actually an important constituent part of culture, just as a liking for or refusal to eat milk products is something that runs through an entire conception of culture. Many customs have revolved around milk products, representing different degrees of wealth and social status. Black koumiss was the classic beverage of the upper nobility in the Mongol-Yuan period, but ordinary dry cheese was the lower level common people’s basic food. Clarified butter that had been through a refinement process one hundred times was the acme of refinement in milk product manufacturing technology. The techniques for the distillation of liquor we have discussed in this paper is probably another important contribution of the Northern nomadic peoples. Although milk products had been basic foods of the northern peoples over a long time, they reached a high tide in the period after the Northern Dynasties to Sui and Tang, and had a profound influence after the Mongols introduced them to Chinese society. However, the nomadic people's experience and love of milk products did not lead to the Chinese people having any large-scale dietary customs of a similar kind. Moreover, such customs failed to take root anywhere in the entire East Asian area. As a result, people have felt deeply puzzled and have been looking at many angles of explanation. However, after we have a thorough understanding of the techniques used, the source of the raw materials, and the method of manufacture and the entire lifestyle and ethos that goes along with it, we begin to understand more or less why such foodstuffs are either popular or not. The formation of the basic foodstuffs of any people are always the result of the wisest and most economical choices available under pressure for survival, and once the breakthroughs in technology have occurred, any food has the potential to spread rapidly to other peoples. Patterns of production under industrialization, and convenience of transportation in modern society, have provided preconditions for further possibilities.