Background: Diabetes is a metabolic disease characterized by increased blood glucose levels, so it could increase the reactive oxygen species (ROS), thus enhancing the expression of tumor necrosis factor- (TNF-) and resulting in insulin resistance. Cinnamon is a plant that has a bioactive component of the class of polyphenols that have activity like insulin (insulin mimic). Method: This study was experimental laboratory with the test subject were healthy white male rat strain Sprague dawley with weight > 150 gram, age 2 months and 25 rats divided into 5 groups. Streptozotocin+nicotinamide induction was performed in the positive control group and the intervention group. Blood sugar levels were measured at both before and after induction. Given 14 days group therapy and TNF- levels were measured three times using ELISA. Differences in levels of TNF- from all groups were analyzed by One-Way ANOVA parametric test on normally distributed data. Results: There was no significantly differences in TNF- levels before treatment (p value = 0.107) and after day 7th therapy (p value = 0.907) of all groups. There was significantly differences in TNF- levels at the time after day 14th therapy (p value = 0.02). Giving cinnamon infusa dose 300 mg/kgBB in diabetic rats showed significant differences of TNF- level between before and after therapy (p value <0,05), whereas at dose 150 mg/kgBB showed no significant differences at before and after therapy (p value> 0.05). Conclusion: Cinnamon infusa at doses of 300 mg/kgBB/day and 150 mg/kgBB/day for 14 days can not decrease TNF- levels in diabetic rats.