Abstract: To clarify the changes of mineral elements of yak milk during the lactation cycle，milk samples at 12 time points from 0 to 180 d during the lactation cycle were collected from Maiwa yak at Longri livestock breeding station in Sichuan province. After milk samples were prepared using microwave digestion，fourteen elements were analyzed by the ICP-OES for four macro elements （potassium，calcium，magnesium，phosphorus） and ten micro elements （boron，barium，cadmium，cobalt，copper，molybdenum，nickel，titanium，zinc，manganese）.The statistical analysis based on the statistics data from the samples on day 30 was proceeded. The results showed that the concentrations of K，Ca，Mg and P in Maiwa yak colostrum were higher.The concentrations of K on day 0 （P＜0.01），120 (P＜0.05），Ca on day 5 （P＜0.05），Mg on day 180 （P＜0.05） had significant differences as compared with that of mineral elements on day 30， but no significant difference was observed in the concentration of P （P＞0.05） during the lactation cycle.The results also suggested that the concentrations of trace elements were significantly affected by the lactation cycle. The concentrations of Ba on day 0 and 1 （P＜0.01)，2，3，4，5 and 180 （P＜0.05），Mo on day 180（P＜0.05），Ni on day 180（P＜0.05），Zn on day 180（P＜0.05） had significant differences as compared with that of mineral elements on day 30，but there were no significant differences on B，Cd，Cu，Ti，Mn during the lactation cycle.In conclusion，the concentrations of K，Ca，Mg，Ba，Mo，Ni，Zn had significant differences during the lactation cycle （P<0.05），but no significant differences were observed in the concentrations of P，B，Cd，Cu，Ti，Mn （P>0.05）.Overall，the concentrations of K，Mg，P，Ba，Zn were all firstly decreasing and then increasing，while Ca content was firstly increasing and then decreasing.

Key words: yak milk; mineral elements; microwave digestion; ICP-OES