Abstract：Objective：To determine the serum levels of miR-342-5p and miR-423-5p in type 2 diabetes (T2DM) patients with or without microvascular complications, and explore their associations with oxidized lipoprotein and other biochemical parameters in serum. Methods：The serum levels of miR-342-5p and miR-423-5p were examined in 50 T2DM patients, 50 T2DM patients with microvascular complications and 50 healthy controls using quantitative real-time PCR (qRT-PCR). The concentrations of ox-LDL, ox-Lp(a), β2-GPⅠ-ox-LDL and β2-GPⅠ-Lp(a) were also measured in the serum samples of the same cohort using enzyme linked immunosorbent assay (ELISA). The levels of fasting blood glucose, triglycerides, cholesterol, high density lipoprotein, low density lipoprotein and others biochemical parameters were determined by biochemical analyzer. Results：The data of qRT-PCR showed that the concentrations of miR-342-5p and miR-423-5p were 0.144 (0.027, 0.487) fmol/L and 1.480 (0.676, 2.580) fmol/L in healthy controls which were significant higher than those of T2DM patients ［miR-342-5p: 0.234(0.103,1.241) fmol/L (U=779，P＜0.01); miR-423-5p: 3.398(1.742,7.351) fmol/L(U=606, P<0.01), respectively］ and T2DM patients with microvascular complications ［miR-342-5p: 0.300 (0.102, 2.760) fmol/L (U=731, P＜0.01); miR-423-5p: 3.886(2.021, 9.430) fmol/L (U=488, P<0.01), respectively］. ROC curve analysis results showed that the area of under ROC curve (AUC^ROC) of miR-342-5p and miR-423-5p were 0.688 (95%CI: 0.586 to 0.803) and 0.702 (95%CI: 0.600 to 0.803) for T2DM patients, and 0.758 (95% CI: 0.664 to 0.851) and 0.801 (95% CI: 0.716 to 0.886) for T2DM patients with microvascular complications, respectively. The ELISA results showed the concentrations of FPG, ox-LDL, ox-Lp (a), β2-GPⅠ-ox-LDL and β2-GPⅠ-Lp(a) levels in serum of type 2 diabetes patients with or without microvascular complications were also markedly elevated when compared with those of healthy controls (all P<0.05). Spearman rank correlation analysis revealed that the levels of miR-342-5p and miR-423-5p were significantly correlated with those of ox-LDL, ox-Lp(a), β2-GPⅠ-ox-LDL, β2-GPⅠ-Lp(a). Conclusion：The levels of miR-342-5p and miR-423-5p were significantly increased in the serum of T2DM patients with or without microvascular complications, which were significantly associated with oxidized lipoprotein. The elevated serum miR-342-5p and miR-423-5p combined with oxidized lipoprotein can be used as novel biomarkers for potential auxiliary diagnosis of T2DM patients and T2DM patients with microvascular complications.