Improving yield is the major component of any breeding programme. Enhancing yield heterosis under aerobic conditions is prime objective of the present study. A field experiment was conducted to study the magnitude of heterosis among twenty four cross combinations developed through line x tester mating design derived from three lines and eight aerobic rice testers. Highest heterotic effect for grain yield per plant was exhibited by hybrid APMS6A/HHZ12-SAL2-Y3-Y2-1 (30.94%) followed by APMS6A/HHZ12-Y4-DT1-Y3 (17%) and IR58025A/HHZ17-Y16-Y3-Y1 (13.46%). In comparison with aerobic standard check CR Dhan 201, hybrids showed relatively better yield heterosis. From present study observed that heterotic response for grain yield per plant was mainly due to high heterotic response observed for productive tillers per plant, panicle length, number grains per panicle, biomass and harvest index. It is clear that yield attributing characters plays a major role in yield maximization simultaneously, best performing parental lines such as APMS6A and IR 58025A could be the potential source of breeding material in development of aerobic hybrids for improvement under aerobic conditions.