Genotype distribution and chemical activity of amylase in a natural population of Drosophila melanogaster were analysed from 201 and 145 iso-female lines in 1988 and 1989. The amylase genotype was used PAGE, and stained by starchiodine method. Seven different patterns of amylase genotype have been found as Amy 1, 1.2, 1.3, 1.6, 1.2.3, 1.3.4 and 1.3.6. Among these genotype, Amy 1 was confirmed to be the commonest and ancestral allele which frequency observed 73.13% and 73.79% in 1988 and 1989. Amy 1.6 appeared only 0.69% in 1989. Chemical activity of each amylase genotype was determined by DNSA reaction and confirmed by Shimazu UV vis spectrophotometer. The highest protein concentration showed in Amy 1.6 strain (6.976 × 10^(-3) ㎎/㎕), and Amy 1.2.3 strain was the lowest value (3.980 × 10^(-3) ㎎/㎕) among all of the amylase allele. The highest glucose content have shown Amy 1.6 strain (260 × 10^(-5) ㎍ ㏖/㎕), and that of the lowest was Amy 1 strain (40 × 10^(-5) ㎍ ㏖/㎕) among seven amylase genotype.