Seven multivoltine lines and four bivoltine lines of silkworm were crossed in line x tester fashion to synthesise 28 multivoltine x bivoltine hybrids. These hybrids were evaluated for general and specific combining ability effects and their variances for silkworm seed technological traits in replicated trial. The multivoltine lines, Kollegal Jawan (KJ) and Kolar Gold (KG) were found to be good general combiners for rate of pupation, fecundity and pupal weight whereas Hosa Mysore (HM) for rate of pupation and rate of moth emergence, respectively. The bivoltine testers, Kalimpong-A (KA) and NB4D2 were identified as desirable general combiners in common for rate of pupation, fecundity, pupal weight and rate of moth emergence. The crosses, Nistari x NP2 and PM x NB4D2 showed their superiority for specific combining ability for all the seed technological traits studied except rate of moth emergence and fecundity. The hybrid Thai x KA expressed good specific combining ability for pupal weight and rate of moth emergence. Predominance of non-additive gene action in the inheritance of seed technological traits was vivid.