In order to improve the yield of 3-acetylpyrrole-2 carbexylic aeid(APCA) through the Knorr condensation of ethyl acetopyruvate(EAP) with aminoacetaldehyde(AAL), the effects of solvent, reaction temperature and pH were examined. The following conclusions were deduced from these results, (1) The more homogeneous is the reaction system made by the solvent, the higher is the yield of (APCA). (2) The yield of the Knorr condensatien is optimum at 35C and at pH 4.3. (3) The enamine intermediate is formed by the reaction of (EAP) rith aminoacetal(AA)competing with the Knorr condensation. The structure of enamine intermediate is identified by IR spectra and the elementary analysis. (4) (APCA) is obtained by the ring losure of enamine intermediate.