Abstract: In 1983-1984 we compared the isoenzyme patterns of lactate dehydrogenase, malate dehydrogenase, esterase, glucose-6-phosphate dehydrogenase and peroxidase of Anopheles sinensis from Xuzhou, Yixing, Fuzhou and Haikou by polyacrylamide gel electroph oresis and esterase isoenzymes, proteins, sugars and lipids of An. sinensis by isoelectric focusing. The results are as follows: (1) No significant difference was observed among these four local populations in PAGE isoensyme patterns of the 5 enzymes studied; (2) As a whole, the patterns of esterase isoenzymes by IEF showed no difference, H= - 2.244, p0.05, but a geographic difference in individual bands was obvious.It increases with the geographic distance, indicating the presence of intraspecific differentiation; (3) Pro teins, sugars and lipids were essentially similar, with some minor differences in indi vidual protein bands, somewhat similar to those revealed in the IEF pattern of esterase isoenzymes.