The aim: To distinguish the function role of IL-6 protein levels as well as IL-6 (-174) gene polymorphism in diabetes mellitus patients. Materials and methods: in present case-control study160 (cases 86, control 74) volunteers were enrolled in this study 2.5 ml were added to EDTA tube for molecular investigation IL6 (-174), and other 2.5 ml use for measurement of fasted glucose by spectrophotometry and insulin levels as well as IL-6 level by ELISA. Results: Regarding IL-6-174 (rs1800795), results revealed significant difference at genotype CC (p- value 0.05 with odds ratio 3.49) and allele frequency C (p-value 0.02 with odds 2.17), also at protein level the IL-6 showed significant difference between IL-6 levels and T2DM especial in insulin resistance (IR) group (p-value 0.03) compared with control one (Cont). Conclusions: There is potent relation between IL-6 levels with T2DM and IR groups. There is potent relationship between CC variation of IL-6 (-174) and risk of each T2DM and IR condition.