Abstract: Objective: To study the hypoglycemic effect of flavonoid extract from Lonicera japonica Thunb.. Methods: 75% ethanol was used to obtain flavonoid extract from Lonicera japonica Thunb. by ultrasound. Adaptive feeding of mice for one week, then they were divided into normal group, model group, low-dose flavonoid extract (200 mg/kg·BW), high-dose flavonoid group (400 mg/kg·BW), and positive group (200 mg/kg·BW). Except for the normal group, streptozotocin (STZ) (130 mg/kg·BW) was intraperitoneally injected in the other groups at one time, and the gavage was started after the modeling was successful. Bodyweight and fasting blood glucose (FBG) values of mice were recorded and oral glucose tolerance (OGTT) test was performed during the experiment. Serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and malondialdehyde (MDA) were determined in mice. The changes of tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), interleukin (IL-8) and interleukin (IL-6) in mice were investigated by enzyme linked immunosorbent assay (ELISA). Results: The content of flavonoid extract from Lonicera japonica Thunb. was 43.62 mg/g. Compared with the model group, the test group was able to effectively alleviate the weight loss in type 1 diabetic mice (T1DM), and significantly decrease their FBG (P<0.01), significantly increase OGTT level (P<0.01). TC, TG, LDL-C and MDA in the high-dose flavonoid group were significantly lower than those in the model group (P<0.01), and HDL-C, SOD, GSH, and CAT were significantly higher than those in the model group (P<0.01). Compared with the model group, the levels of TNF-α, IL-1β, IL-8, and IL-6 were significantly decreased (P<0.01) after treated with flavonoid extract from Lonicera japonica Thunb.. It was able to improve liver damage caused by diabetes. Conclusion: Flavonoid extract from Lonicera japonica Thunb. had a good hypoglycemic effect and could improve abnormal lipid metabolism, inflammation and liver injury in T1DM mice.