The high performance liquid chromatography(HPLC) method for a simultaneous determination of vitamins in white yak s milk has been developed.By the analysis of vitamins contents of white yak s milk under different seasons and pastures,the results showed that vitamins contents in white yak s milk were largely affected by the different seasons,the contents of vitamin A and E were maximal at the summer time,and they were 46.10 and 104.22μg/100 mL respectively.There were no significant differences for the con...