Wheat (Triticum aestivum L.) is one of the three main cereal crops in the world. It is a staple food and an important source of protein for humans. The gluten protein in wheat grain is the chemical bases for making various end-products. Its processing quality is mainly determined by seed storage proteins that consist of polymeric glutenins and monomeric gliadins. Glutenin proteins are divided into two groups: high-molecular-weight glutenin subunits (HMW-GS) and low-molecular-weight glutenin subunits (LMW-GS). The specific distribution of subunit combinations in the main Chinese wheat growing areas is not clear. This study focuses on the distribution of subunit or allele combinations in the main wheat growing regions of China. In the current study, we analyzed allelic variation at the Glu-1 locus in 1,523 Chinese common bread wheat lines, including 597 landraces and 926 commercial wheat varieties, from the four major wheat-growing regions in China. As results, alleles Null, 7+8, and 2+12 were the dominant HMW-GSs in wheat landraces. Compared to landraces, the commercial varieties contain higher frequencies of high-quality alleles, including 1, 7+9, 14+15 and 5+10. The genetic diversity of the four commercial wheat populations was significantly higher than that of the landraces population, with the highest genetic diversity found in the Southwestern Winter Wheat Region population. The genetic diversity of HMW-GS is mainly present within the landraces and commercial wheat populations instead of between populations. The landraces were rich in rare subunits or alleles may provide germplasm resources for improving the quality of modern wheat.