Introduction: Diabetes mellitus is a chronic disease, resulting from defects in insulin secretion, insulin action, or both. Indonesia ranked 7 out of 10 on countries with the most highest number of diabetic patient. Oxidative stress and high blood glucose level were occurring under diabetic condition. High prevalence of diabetes and expensive cost for treatment lead to development of alternative treatment for diabetes. Alkaline water with pH>7 acts as antioxidant and had been proven to lower blood  glucose level via increase in glucose uptake. Metformin is the first line drugs for type 2 diabetes. The aim of this research was to compare the effect of alkaline water and metformin on blood glucose level of diabetic model rats. Methods: This research was experimental laboratory with the randomized pre and post test controlled-group design. This research was using 24 in total of 2 months old male Wistar albino rats weighting 180-200 g. Rats induced by alloxan 155mg/kg bw on the first day, then randomly divided into 4 groups with different treatments. Negative control group (K-) was given aquadest, positive control (K+) metformin 9mg/200g bw, Alkaline water 1 (Alk1) 23 ml, and alkaline water 2 (Alk2) 46 ml of alkaline water. These treatment was given once daily on the 5th until 12th day. Blood glucose level was measured three times: before induced by alloxan, after induced by alloxan, and post-treatment. Data were analyzed using repeated measures ANOVA (α = 0.05) followed by Multiple Comparisons LSD (α = 0.05). Result: The mean of post-treatment blood glucose level on K-, K+, Alk1, Alk2  respectively (in mg/dl) were 242.33±50,06; 67.83±12.90; 71.83±8,37; 70.83±9.72. The result of Repeated Measures Anova showed significant difference on mean blood glucose level (p=0.000). The result of LSD on mean of blood glucose level reduction showed significant difference (p=0.000) between K- and K+, K- and Alk1, K- and Alk2. The results of LSD showed no significant difference between K+  and Alk1 (p=0.536) as well as K+ and Alk2 (p=0.280).Conclusions: Alkaline water has comparable effect with metformin on blood glucose level of diabetic model rats.Keywords: alkaline water, metformin, blood glucose level, alloxan