Core collection represents a maximum of the genetic diversity of the whole collection with a minimum of accessions and a minimum of redundancy. In order to test sampling of core collection, the study chose two groups at random among the core collection in Huanghuai summer sowing soybean, with 20 and 14 accessions , respectively; and selected 6 and 5 accessions respectively among the two groups of the reserve collection in Huanghuai summer sowing soybean, torally 45 materials. The study made use of 14 agronomic characters and 20 pairs of SSR primers. The core collection and the reserve collection were clustered together. The two groups in the core collection had 129 and 136 alleles, and the two groups in reserve collection had 76 and 71 alleles. The core collection add up to 86.00% and 86.62% of the diversity of the whole collection. The result indicates that the core collection include genetic diversity of the reserve collection at 70% level. The study provides the proof at molecular level for the evaluation of the availability of the core collection in soybean.