Abstract: Milk is a natural source of kinds of fatty acids, which play important roles in the process of metabolism. FA in milk originated from de novo synthesis in mammary gland and blood directly. It varied with many factors, such as genetic, feed, lactation stage and age, season, farming, flock effect, etc. This article has reviewed fatty acids synthesis and correlation among them, of course, factors affected FA were also included.

Key words: milk; fatty acids; influencing factors