An integrated process of cefaclor synthesis from phenylglycine methyl ester (PGME) and 7-aminodesacetoxymethyl-3-chlorocephalosporanic acid (7-ACCA) catalyzd by penicilin G acylase (PGA) with in situ product removal (ISRP) was estbilshd. The ntegrted process was more significantly influenced by temperature than the separate synthesis process as without ISPR. The difference between the overall yields with and without ISPR was minfied as reaction temperanres rose. For instance, the maximum 7-ACCA comversions was 86 and 68%, respectively, in the process with and without ISPR at 5℃. Both the maximum conversions. however, decreased to around 45% at 40℃. The effect of substrate concentration on the overall converion was also obviously dependent on the reaction temperiature. Te product cefaclor inhibited PGME hydroplysis in the enzymatic syathesis. ISPR stimulated cefacor synthesis at lower temperatures, but was not useful at hight temperatures which accelerated PGME hydrolysis.