Four genotypes of soybean (Glycine max (L.) Merril), namely, H3Z, H30Z, H73ZBC and H75ZBC, were used as females top crossed to each of the three different genetic base testers (male), namely, Gasoy, Hartwig and H5L23. The following characters were measured: plant height, number of branches per plant, number of days to flowering, number of days to maturity, number of pods per plant, number of seeds per plant, 100-seed weight and seed yield per plant. The mean squares due to parents, crosses and lines (females) by testers (males) were highly significant for all the studied traits. Relative estimates of the variance due to general combining ability (d²gca) and specific combining ability (d²sca) indicated that (d²sca) played a major role in the inheritance for all traits. The parental H5L23 (tester) gave the highest positive and higher significant “” effect than other two testers for number of pods per plant, number of seeds per plant and seed yield per plant. The female line H30Z behaved as good combiner for all studied characters, except 100-seed weight. Significant positive “sca” effects were detected for number of pods per plant, number of seeds per plant and seed yield per plant in two crosses, i.e., (H30Z x Hartwig) and (H73ZBC x Hartwig). All crosses showed highly significant positive heterotic effects relative to mid and better parent values for yield and its component characters.