The purpose of this paper is to understand the milk processing system practiced in the Mongolian nomadic Khalkha groups of Su'qbaatar and Dornod Provinces in eastern Mongolia through a field survey, to compare it with surrounding areas of Qentiy and Dundgowi Provinces, and then to analyze the transmission of processing techniques by further comparison with those of Syria, Jordan, Iran and Iraq in West Asia. The milk processing techniques of fermentation, cream separation and additive coagulation are all used in Su'qbaatar and Dornod Provinces. In fermentation processes, the technique of alcohol fermentation with churning is mainly used for cow milk to process alcoholic sour milk, followed by further processing to spirit, butter oil and non-matured dry cheese. In cream separation processes, the technique of heating/cream separation is used, in which cream is first separated from milk and non-matured dry cheese is processed from skim milk. In additive coagulation processes, the technique of fermented milk coagulation which utilizes lactic acid fermented whey as a coagulant is used to process non-matured dry cheese. These techniques are widely shared in the eastern part of Mongolia. It is characteristic of Su'qbaatar Province that the processing of cow milk is dominated by the technique of fermentation processes, mainly alcohol fermentation with churning. It is presumed that the technique of churning sour milk transmitted from West Asia to eastern Mongolia, and then the function of churning originally for butter processing was converted to allow for alcohol fermentation under the cooler environment in North Asia.