The aim of this study was to establish an accurate and effective method for determining Vitamin K1 in dairy products. After extraction,the samples were analyzed by C18,with methanol as mobile phase. The absorption wavelength of 248 nm was chosen to detect vitamin K1. The results showed that calibration curves were linear between0 ~ 4. 0μg / m L,and the correlation coefficients were 0. 9996. The recoveries of the vitamin K1 in the dairy products were more than 90. 0% with relative standard deviations less than 2. 0%. This method is better than the national standard method GB 5413. 10-2010 in terms of precision and recovery. In addition,it can simultaneously determine the level of vitamin A,vitamin D and vitamin E. This is an effective and accurate method for determination of vitamin K1.