Objective:Two kinds of titration methods (automatic potentiometric titration and indicator titration) of GB 5009.229 and GB 5009.227 were used to analyze the expanded uncertaintyof the determination of acid value and peroxide value in edible oil.Methods:CNAS-GL006 was used for the uncertainty component and extended uncertainty of the measurement results of the two titration methods.Results:The results showed that the standard solution was the main factor affecting the uncertainty of acid value (value) and peroxide value.Conclusion:The effects of the two titration methods on peroxide value and acid value (value) of edible oil is relatively small, and the appropriate titration method can be selected according to the actual situation for the basic testing organization.