Twenty-nine traditional fermented yak milk (kurut) and 15 traditional fermented Mongolian cow milk (FMCM) samples were collected from three regions of Tibet in China, and their chemical composition and microbiological properties were analyzed. Average levels of the major composition of kurut and FMCM, respectively, were as follows: total solid, 16.91+/-1.30 g/100 g and 12.65+/-1.14 g/100 g; fat, 6.83+/-1.18 g/100 g and 3.92+/-0.92 g/100 g; total protein, 4.93+/-0.36 g/100 g and 3.33+/-0.71 g/100 g; free amino acid, 8.57+/-3.22 mmol/l and 2.23+/-0.62 mmol/l; calcamin, 117.26+/-9.66 mg/100 g and 86.51+/-7.55 mg/100 g; and phosphorus, 109.28+/-7.97 mg/100 g and 78.86+/-6.99 mg/100 g. The average bacteria count of lactic acid bacteria in kurut and FMCM were 7.66+/-0.71 and 8.03+/-0.68 log colony-forming units (cfu)/ml, respectively. Moreover, the average yeast counts of these two samples were 6.48+/-0.81 and 5.92+/-0.52 log cfu/ml, respectively. The result showed that the major nutritional composition content of kurut was significantly higher than that of FMCM, which indicated that kurut can be considered an invaluable fermentation product for human being.