Combining ability analysis , heritability and heterosis were studied for earliness, as well as maturity , yield and some of its components in five diverse soybean (Glycine max “L." Merril) genotypes, which were crossed in a dillel mating pattern. Results revealed significant differences among the 25 genotypes, for all, the studied traits. General and specific combining abilities were also significant except for number of seeds/pod and 100-seed weight in g.c.a., indicating the importance of both additive and non-additive gene effects. The genotype MBB 80-133 was positively a high general combiner for all attributes except number of days to flowering and maturity. It was the best parent for seed yield /plot. The crosses (MBB 80-133 X H15 L4), (MBB 80-133 X H2L24) and (H2L24 X L35) were found to exhibit high positive specific combining ability effects for number of seeds/pod, seed filling period and seed yield/plot, in the same order.  For seed yield/plot the cross (H2L24 X L35) showed positive significant reciprocal effect. The highest value for broad sense heritability was found for number of days to maturity . The mid-parent and better parent heterosis were significant for all the characters. For seed yield/plot, most of the crosses gave more yield than their mid-parent values. The cross (MBB 80-133 X H2L24) showed the highest heterosis over mid and better parents 47.99 and 29.12% , respectively.