Thirty hybrids generated from crossing five lines with six testers were studied along with parents for combining ability and gene action involved in expression of characters in aerobic rice. The gca and sca effects were significant for all the characters indicating the importance of both additive and non-additive genetic components There was predominance of non-additive genetic components for expression of different traits in the present set of materials. Amongst the parental lines, IR 73718-3-1-3-3 and CT-6510-24-1-2 were best general combiners for grain yield along with other traits. The most specific combiners for grain yield and other traits were IR 67684A /CT-6510-24-1-2, IR 68885A / IR 73718-3-1-3-3, IR 70372A / PSBRC 80 and IR 70369A / IR 73718-3-1-3-3.