Objective:To investigate the relationship between histone deacetylase (HDAC) gene polymorphism and type 2 diabetes mellitus (T2DM) in Bai and Han populations in Dali of Yunnan province.Methods:A total of 148 patients with T2DM of Bai and Han nationalities who received treatment in Dali Bai Autonomous Prefecture People's Hospital from May 2019 to March 2021 were included in the T2DM group. An additional 100 healthy controls of Bai and Han nationalities who concurrently received physical examination in the same hospital from May 2019 to December 2020 were included in the normal control group. The susceptibility genes of T2DM were detected using the Taqman MGB probe method. The susceptibility gene loci were amplified using polymerase chain reaction. The whole sequence of susceptibility gene was sequenced.Results:There were no significant differences in the distribution frequencies of rs2530223 genotype, rs11741808 genotype, rs2547547 genotype, and rs1741981 genotype between Bai and Han populations (all P > 0.05). There was a significant difference in blood lipid level between four loci ( t = -1.06, -0.19, 0.39, -2.12, -2.04, 0.16, 1.47, < 0.01, -0.16, -3.17, -2.93, 0.69, -2.58, -2.33, all P < 0.05). There was a significant difference in homeostasis model assessment of insulin resistance between different states (all P < 0.05). The frequency distributions of each genotype and each allele did not differ significantly between healthy control people of Bai nationality and T2DM patients of Bai nationality and between healthy control people of Han nationality and T2DM patients of Han nationality (all P > 0.05). Logistic regression analysis showed that the polymorphism was not an independent risk factor for T2DM. Conclusion:The relationships between HDAC gene polymorphism and T2DM, obesity and dyslipidemia differ between Bai and Han populations.