Line x tester analysis of 28 crosses obtained from seven lines and four testers were made to estimate the combining ability for yield, water use efficiency and its attributing traits in mungbean. Lines LM 567, SML 134, ML 347 and BL 866 were the best combiners which scored significant positive gca effects for most of the characters studied and among testers KKM 3 was the best combiner compared to rest. Hence which can be further tested for their use in mungbean breeding programme for improvement of yield. Fifteen hybrids out of twenty eight scored high status for sca effects indicating predominance of non-additive gene action in the inheritance of the characters studied. None of the hybrids showed significant sca effect for traits ? 13C value, SLA and SCMR indicating the additive gene action for these traits. The highest total score over the final norm was recorded by the hybrid BL 866 × VGG 4 followed by BL 862 × VGG 4, LM 567 × KKM 3, Hg 19/A × GM 8413 and BL 866 × NP 36. Hence, these crosses can be utilized for exploitation of heterosis.