Diabetes mellitus is a chronic disease that occurs when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces. Hyperglycemia or an increase in blood sugar levels is a common symptom of uncontrolled diabetes. Chirinyuh plant (Chromolaena odorata L.) has been traditionally used to treat diabetes. This study aims to determine the effect of 70% ethanol extract of chirinyuh (Cromolaena odorata L.) leaves on decreasing blood sugar levels in white rats (Rattus norvegicus) wistar strain induced by sucrose. Rats were divided into 5 groups, namely negative control induced 0.5% Na-CMC, positive control induced glibenclamide, dose I 175 mg / kg body rat, dose II 200 mg / kg rat and dose III 225 mg / kg rat.Based on the results of the post hoc analysis test Student-Newman-Keuls decreased blood sugar levels there was a significant difference (p> 0.05) between the negative control group and all treatment groups. Whereas in the decrease of positive control blood sugar levels with group I dose, dose II and dose III showed no significant difference. As for the value of a decrease in blood sugar levels were greater in a row that is dose III (225 mg / kg body weight rats), dose I (175 mg / kg body weight rats), dose II (200 mg / kg body weight rats) and positive control group ( glibenclamide). Decrease in blood sugar levels shows that group dose III (225 mg / kg body weight mice) has a greater effect on reducing blood sugar levels. Keywords: Diabetes mellitus, chirinyuh leaf, blood sugar level, Rattus norvegicus.