All F1 males were investigated from 261 TP and 280 TY isofemale. Sterility frequencies from these populations were 0.65% and 1.30% in cross A. The mean sterility frequencies tested isofemale lines were 39.3550 and 35.6100 in cross A°. Most strains in TP and TY populations were mostly found to be M` and Q strains. True M strain was low frequency in four populations and P(M) strain was also very low frequency in three population except for TY. GD sterility frequency of flies with In(3R)P was only M' and Q strains. Though the normal flies collected in wild populations observed lightly GD sterility in true M and P(M) strains, the flies with In(3R)P were no observed. Therefore P activity in Q and M' strains seems to be observed higher in flies with In(3R)P except for TY populations. P activity of true M and P(M) strains were only in normal flies of isofemale lines.