| In order to clarifying the distribution of grain weight genes in Qinghai plateau cultivars. In this study,KASP marker was used to detect the distribution of allelic variants of the three grain weight genes( TaCwi-A1, TaTGW6-4A and TaGW2-6A) in 49 wheat cultivars in the Qinghai Plateau over the years,The thousand-grain weight (TGW) was investigated to analyze the influence of different allelic variation combinations on wheat grain weight,and the best genotype combination was explored. The results showed that there were significant differences of TGW among the 49 wheat cultivars in different years. At the TaGW2-6A locus, TaCwi-A1a and TaCwi-A1b allelic variations were detected,and their distribution frequencies were 69.39% and 30.61%,respectively. At the TaTGW2-6A locus, Hap-6A-A and Hap-6A-B allelic variations were detected,and their distribution frequencies were 46.94% and 53.06%,respectively. At the TaTGW6-4A locus, TaTGW6-4Aa and TaTGW6-4Ab allelic variations were detected,and their distribution frequencies were 97.96% and 2.04%,respectively. The different allelic variations of TaCwi-A1, TaGW2-6A and TaTGW6-4A loci caused significant changes in TGW of wheat. Among them,the allelic variation of TaCwi-A1 locus has a more important influence on TGW. Among the 49 wheat cultivars,the distribution frequency of TaCwi-A1a/ Hap-6A-A/ TaTGW6-4Aa genotype was 32.65%,with the highest average of TGW,which was significantly higher than other genotypes. Therefore,the TaCwi-A1a/ Hap-6A-A/ TaTGW6-4Aa genotype is the more preponderant genotype combination.