To study the therapeutic effect of Jerusalem artichoke particles in type I and type II diabetic rats. Male Sprague–Dawley (SD) rats were intraperitoneally injected with 30 mg/kg streptozotocin (STZ) for 3 consecutive days to generate a type I diabetic rat model. The rats were orally administered Jerusalem artichoke particles (50, 100, or 150 mg/kg) once a day for 3 consecutive weeks. Fasting blood glucose levels were determined by ELISA. Male SD rats were fed a high-fat and high-sugar diet then received an intraperitoneal injection of 35 mg/kg STZ to generate a type II diabetic rat model. The rats were treated as mentioned above for 4 consecutive weeks. Fasting blood glucose levels were determined using the glucose oxidase method. Jerusalem artichoke particles significantly reduced blood glucose concentrations in type I and type II diabetic rats. Following 50, 100 and 150 mg/kg Jerusalem artichoke particles treatment for specified weeks, blood glucose concentrations were decreased by 9.7%, 21.69% and 15.48% in type I diabetic rats, respectively; and type II diabetic rats were decreased by 12.07%, 28.57% and 21.80%, respectively. Jerusalem artichoke particles have a hypoglycemic effect in type I and type II diabetic rats.