Deacidification of high-acid rice bran oil catalyzing by esterification using lipase Novozym 435 were studied. According to response surface method (RSM) and Box—Benhnken experimental design, the best conditions of enzymatic esterification were optimized based on the analysis of significant factors and their interactions. The optimum conditions were：enzyme concentration of 1.1%, initial glycerol of 0.42mg, reaction temperature of 56.4℃, the reaction time of 23.2h. Under the conditions，rice bran oil acid value（KOH） decreased from 56mg/g to 5.04mg/g，the esterification rate of free fatty acid（FFA） reached to 91% and matched the prediction value by model.