Objective:To analyze the differences in the composition of Plantagoasiatica L.seeds and Plantagodepressa Willd. seeds and compare their therapeutic effects on C57BL / 6 diabetic mice induced by STZ(streptozotocin)in order to provide an experimental basis for the quality evaluation on Plantaginis Semen. MethodsThe composition of Plantagoasiatica L.seeds and Plantagodepressa Willd. seeds were compared qualitatively by TLC. A quantitative method for the determination of geniposidic acid and acteoside was established by HPLC. At the same time,the diabetic model was made by intraperitoneal injection of STZ in mice. After drug intervention,fasting blood glucose was measured,blood and pancreatic tissue were collected,serum biochemical indexes were measured,and the effects of two different primordial plantain on the model mice were compared.  Results:The results of chemical composition analysis showed that the seeds of Plantagoasiatica L.and Plantagodepressa Willd. contain not only phenylethanolic glycoside acteoside,iridoid terpenoid geniposidic acid,plantagoamidinic acid A,but also other specific components. The content of geniposidic acid and acteoside in Plantagoasiatica L. seeds was significantly higher than in Plantagodepressa Willd. seeds by HPLC. In the experimental diabetic mice,the weight of the mice was significantly increased in both groups of Plantagoasiatica L.seeds and Plantagodepressa Willd. seeds,the blood glucose was significantly reduced,the total serum antioxidant capacity was enhanced,and the overexpressed TNF-α and IL-1β in serum was decreases(P<0.01). Among them, Plantagoasiatica L.seeds could significantly reduce blood glucose of mice than Plantagodepressa Willd. seeds, and could increase the content of insulin in serum and repair the damage of islet β cells(P<0.05),while Plantagodepressa Willd. seeds had no obvious effect.  Conclusion:The chemical constituents of Plantagoasiatica L. seeds and Plantagodepressa Willd. seeds are different and the contents of geniposidic acid and acteoside in Plantagoasiatica L.seeds are higher than those of Plantagodepressa Willd. seeds. Both Plantagoasiatica L. seeds and Plantagodepressa Willd. seeds have good effects on STZ induced diabetic mice model. However,the effect of Plantagoasiatica L. seeds is better than that of Plantagodepressa Willd. seeds.