Five indica photo-thermo sensitive genic male sterile (PTGMS) lines as female parents and 5 restorers lines as male parents were used to make 25 F 1 hybrids by diallel cross to study the combining ability and standard heterosis of 10 agronomic traits. The results showed that the characters of PTGMS lines are determined by the effects of general combining ability (GCA) and specific combining ability (SCA) of both the sterile and restorer lines and the GCA was found to be more effective. Pei'ai64S was the best general combiner among sterile lines followed by NS30g, while the Minghui63 was the best general combiner among the restorer lines followed by Sh623. Significant differences in combining ability among the sterile lines and positive correlation between the values of GCA and standard heterosis of hybrids were observed. The higher GCA of parents exhibited stronger standard heterosis in hybrids.