Fifteen genotypes as lines and three varieties as testers of mungbean were studies in line x tester analysis. The study revealed that the gene action involved in controlling characters namely, days to flowering, days to maturity and seed yield per plant was additive gene action. While other characters viz., plant height, number of clusters per plant, number of pods per plant, pod length, number of seeds per pod, 100-seed weight and protein content were under the control of non-additive gene action. Genotype HUM 1 was found good general combiner for six characters including seed yield. None of the testers found good general combiner for all the characters. Crosses HUM 10 x Kopergaon, Pusa 9331 x K 851 and SML 395 x Gujarat Mung 3 exhibited highly significant positive sca effects coupled with significant positive standard heterosis for seed yield per plant.