Abstract: Comparative analysis of yak milk with other mammalians(ruminant,equine,camel and human) milk on milk yield,lactation and nutritional ingredients(protein,fat,lactose,dry matter,ash,minerals and vitamins). The results showed that dairy cow had the longest lactation and the highest milk yield,there were interspecific differences of nutritional ingredients in milk,but had the species characteristics. Ruminant milk owns higher protein,fat,dry matter and ash than other milk and minerals and vitamins elements,nutritional ingredients content of camel milk were between ruminant milk and equine milk,lactose of equine milk was higher,human milk on each nutritional ingredients except lactose were generally lower than other mammalian milk.