When ethanol is used as the solvent for didecanedioic acid recrystallization,it can react with the acid to form ester,thus reduce the recrystallization product purity. The major factors for the degree of esterification include dodecanedioic acid concentration,ethanol concentration,temperature and time. In this paper,changes of ester generation over time under different temperature and different ethanol concentration were investigated,the effects of ethanol concentration,temperature and time on the degree of esterification were designed with orthogonal experiments. It was found that the effect order was: temperature > time > ethanol concentration,where the influence of temperature was significant. In addition,combinations of factors for minimum and maximum degree of esterification were obtained.Under these conditions,the purity,esterification degree and crystal morphorlogy of recrystallized dodecanedioic acid were examined. It was found that the purities of recrystallized acid were 97. 26% and 97. 50%,and the esterification degrees were 0. 06% and 0. 20% under minimum and maximum esterification conditions respectively. The crystal habit had been improved after recrystallization..