Candidate core collections of common wheat ( Triticum aestivum L. ) were established based on the geographical regions, ecotypes, 21 agronomic and botanic characters of basic collections (entire). The modern varieties were divided into 10 regions, the landrace into 28 sub-regions. In each region or sub-regions, numbers of entries were decided based on the square root of the basic collections with minor adjustment according to the genetic diversity and genetic richness indexes. Varieties or lines having made great contribution in the national wheat breeding and production are priority entries in sampling. The candidate core collections were established after all entries were re-planted and checked in the field. In the candidate core collections, there are 3283 landraces, and 1684 modern varieties, which takes 28.18% and 14.9% of the basic collections respectively. We are going to concentrate the candidate core collections to 10% of the basic collection by molecular markers. They will be the core collections of Chinese wheat germplasm. Statistics showed that there was no significant difference on variation between the candidate core collection and the basic collections except the awn and glumes. The corner mountainous region between the Southern Shaanxi and the Western Hubai, valley along Fenghe and Wei-he are the genetic diversity center of Chinese wheat landrace. In the modern varieties, Southwestern winter wheat region and Huang-huai winter wheat region have the highest genetic diversity.