Abstract: Objective To study the metabolic 9,10-dihydroxystearic acid（DHSA） produced by oleic acid（OA） in mice. Methods Thirty Kunming male mice at the age of 4 weeks were randomly divided into three groups.Ten weeks after the mice were fed with ordinary food,food containing 13% olive oil and food containing 13% bean oil,respectively,12-hour fasting blood was collected to measure the levels of OA and DHSA in serum and erythrocyte membranes. Results The levels of OA and DHSA in serum and erythrocytes membranes were significantly higher in the group fed with olive oil than in the other two groups（P＜0.05）.No significant difference was found in the levels of OA and DHSA between the group fed with bean oil and the group fed with ordinary food. Conclusion DHSA can be produced by the conversion of OA in mice.