Abstract: Trace elements（including iron, zinc, selenium, copper, manganese and iodine）are extremely important for yak growth and development.Trace elements deficiency in yaks can lead to slow growth, reduced immune function, and ultimate impact on health and productivity. Severe deficiency can also lead to death.The author reviewed the effects of trace elements on rumen fermentation and production performance of yaks, the relationship between trace elements in soil, herbage and yak body, and the changes of trace elements content in herbage.The way of supplementing trace elements in yaks was discussed in order to provide reference for the development of trace elements supplement in yaks.