Electrophoretic spectrum of phenoloxidase was studied in 5 wild type and 17 mutant lines of D. melanogaster. Low-molecular alcohols (methanol, ethanol, and isopropanol) proved to be activators of the enzyme. Separate components of the phenoloxidase complex were activated by different agents. Electrophoretic spectrum of phenoloxidase was identical in larvae of 3rd age and 24-hour pupae. It consists of three fractions (A1, A2, and A3). Only the A1 fraction was seen on electrophoregrams of imago. No sex or age differences in phenoloxidase spectrum were observed during 25 days after birth. According to the A1 fraction polymorphism there were both normal and mutant genes coding for the A1 phenoloxidase subunit. The Dox-A1 gene that controls monophenoloxydase is located on the 2nd chromosome and is not linked with Dox-A2 and Dox-A3 genes coding for diphenoloxidases.