The improved determination method was tested by adding Wijs reagent and 10 mL 3% magnesium acetate solution as catalyst reacting for 13 min,according to the principle and operation method of national standard for determination of iodine value in edible oil(Wijs method).The results showed that there was no great difference between the two methods with the relative error less than 2%.It indicated that catalyst magnesium acetate had no adverse effect on the accuracy of determination results.The improved method,possessing less toxicity,good accuracy and reliability,is a rapid method for determination of iodine value in edible oil.