Objective:To study the association of RAC1 gene polymorphisms with protein expression levels of Rac1-GTP. Methods:A total of 182 healthy Hans population in Hubei were recruited. The 4 tag-SNPs in RAC1 gene were genotyped by Real time TaqMan-MGB genotyping assay. And the Rac1-GTP protein levels in plasma samples from all participants were determined by enzyme linked immunosorbent assays ( ELISA ) . The distribution characteristics of Rac1-GTP expression levels were also analyzed. Furthermore,the expression levels of Rac1-GTP were compared among different genotypes of the 4 tag-SNPs in RAC1 gene. Results:The distribution of Rac1-GTP expression levels was positive skewed in healthy Chinese Hans population. The expression levels were significantly higher in females than in males (P<0. 05),and appeared in decreased trend with age,but without significant differences (P>0. 05). Different expression levels of Rac1-GTP were observed in different genotypes for rs702482 and rs10951982 (P<0. 05). However,no significant difference was found for rs702483 and rs6954996 (P>0. 05). Conclusion:RAC1 genetic polymorphisms can potentially affect the expression levels of Rac1-GTP protein in healthy Chinese Hans population.