In Drosophila melanogaster Amy variants were screened for spatial variation in adult and larva midgut α-amylase(E.C. 3.2.1.1; Amy). Enzyme activity was detected by DNSA method during 10 generations in each food component for dietary control. Every strain revealed a different activity in each restricted medium, indicating that each strains have different adaptation ability to carbon source. The relationship of Amy genotype and midgut amylase-activity pattern(Map) analysis was shown expression of MapP indicated highly enzyme activity at anterior parts of region than that at posterior. This suggests that somehow Amy genes, or their products, are differentially recognized by products of the Map gene in addition to being differentially recognized in different parts of the midgut.