Abstract: The experiment was conducted on natural pasture on north bank of Tekes River in army horse farm of Zhaosu County in Yili Kazak autonomous prefecture of Xinjiang from May 15th to September 21th of 2008.55 4-month-old Kazak male lambs were selected to measure the body weight.Among them,20 lambs were used in digestion experiment and 35 lambs were used in slaughter experiment.The preliminary trial lasted for 8 days and the test lasted for 120 days.The results showed that the content of Cu in the muscle of Kazak grazing lambs obviously decreased with the increase of the age and the body weight（P〈0.05）.The content of Cu was the lowest at 6-month-age and reached the highest value at the 7-month-age.The content of Fe significantly increased with the increase of the month-age（P〈0.05）.Fe content reached the highest peak at the 7-month-age and began to decrease obviously at 8-month-age with significant difference（P〈0.05）.The content of Ca continuously decrease at 5-month-age and 6-month-age,without significant difference（P〉0.05）.And Ca content began to increase at 7-month-age,but there was no significant difference（P〉0.05）.The content of Co was basically stable,but it began to decrease at 7-month-age without significant difference（P〉0.05）.The content of Mg basically tended to be stable with the age and there was no significant difference among different months（P〉0.05）.The content of Mn decreased with the month-age,but it began to increase at 7-month-age.Mn content at 7-month-age had significant differences with that at 5-month-age and 8-month-age（P〈0.05）.And Mn content obviously decreased at 8-month-age（P〈0.05）.Zn content obviously increased with the month-age until 6-month-age.Zn content at 6-month-age had significant difference with that at 4-month-age and 5-month-age（P〈0.05）.Zn content began to decrease at 7-month-age and 8-month-age and there was significant difference between 6-month-age and 8-month-age（P〈0.05）.