In order to clear early the agronomic traits selection basis in space flight soybean and improve the early space flight breeding generation selection effect. Analysis of variation rate for SP2 and selection effect for SP4 after space flight for six soybean breed have been done. The result show that the variation rate of higher heritability for the plant pod and seed number of SP2 and choice plant of SP4 were highly significant level. The variation rate of not high heritability for plant height and the number of node and choice plant of SP4 were not significant. The agronomic traits selection of SP2 were effective for the number of plant pod and seed, the first pod hight, the Length of node but for plant height and the number of node.