Augmented randomized complete block test was conducted to evaluate the heterosis of 80 hybrid combinations from TGMS line 402S and its original parent Xiangyou 91S,and the combining a-bility of 40 testcrossing lines.The results of identification test showed that among 47 combinations yielding over the control Xiangyou 15,17 ones with 402S and 3 ones with Xiangyou 91S overyielded more than 20%,reaching the significant level of 1 %;and among 51 combinations yielding over their corresponding higher yield parents,18 ones with 402S and 9 ones with Xiangyou 91S overyielded at 5% or 1% significant level.The test for the GCA effect of all parents indicated that 402S possessed a stronger combining ability than Xiangyou 91S on yield,ailiquae of main inflorescence,total siliquae per plant,seed yield of single plant and 1000 seed weight.10 testcrossing lines with high GCA were picked out for next testcrosses.Among 8 agronomic traits,total siliquae per plant and seed yield of single plant were regarded as the key se Augmented randomized complete block test was conducted to evaluate the heterosis of 80 hybrid combinations from TGMS line 402S and its original parent Xiangyou 91S, and the combining a-bility of 40 testcrossing lines. The results of identification test showed that among 47 combinations yielding over the control Xiangyou 15,17 ones with 402S and 3 ones with Xiangyou 91S overyielded more than 20%, reaching the significant level of 1%; and among 51 combinations yielding their corresponding higher yield parents, 18 ones with 402S and 9 ones with Xiangyou 91S overyielded at 5% or 1% significant level. The test for the GCA effect of all parents indicates that 402S possessed a stronger combining ability than Xiangyou 91S on yield, ailiquae of main inflorescence, total siliquae per plant, seed yield of single plant and 1000 seed weight.10 testcrossing lines with high GCA were picked out for next testcrosses. Among 8 agronomic traits, total siliquae per plant and seed yield of single plant were rega rded as the key se