Combining ability study was carried out in rice (Oryza sativa L.) for days to 50% flowering, plant height, panicle length, number of panicles per plant, number of grains per panicle, spikelet fertility percentage, 1000-grain weight and grain yield per plant, by following the line x tester analysis, involving four CGMS lines, 11 testers and resulting 44 rice hybrids. The analysis revealed the predominance of non-additive gene action for most of the characters under study. This suggests the possibility of exploiting heterosis in the present material. Among the CGMS lines studied, IR 68897A was a good general combiner for days to 50% flowering, plant height and grain yield per plant, CGMS line IR 68888A was a good general combiner for the number of panicles per plant and panicle weight, CGMS line IR 79156A was also good general combiner for panicle length. Tester KMR-3 was found best general combiner for grain yield per plant followed by IR 32809 and IR 65483. Eight cross combinations exhibited high SCA effects for grain yield per plant. These crosses were found to involve at least one parent with high GCA effect and other parents having either high or low GCA effect indicating the involvement of additive as well as non-additive gene action operating in these crosses.