This study was carried out by Non-Clinical Evaluation Center of Biomedical Research Institute, Chonbuk National University Hospital, South Korea to investigate the preventive efficacy of Gryllus Bimaculatus extracts "D&D" in Streptozotocin-induced T1DM rats. Among nine weeks male STZ-induced(65mg/kg) diabetic Sprague-Dawley rats, STZ-induced diabetic rats were randomly divided equally into six groups: Control, high-dose D&D and untreated diabetic rats, D&D (1.63, 3.25 and 6.5g/kg) and treated through oral gavage for 4 weeks. Diabetic related biomarkers were investigated using biochemical and immunohistochemical analysis. Treatment with D&D markedly improved the blood glucose level which was analyzed by intraperitoneal glucose tolerance test (IP GTT) and Insulin tolerance test (ITT). At the end of the experimental period, expression levels of phospho-mammalian target of rapamycin(mTOR), B-cell lymphoma 2(Bcl-2), Bcl-2 associated X protein (Bax) and phospho-serine and threonine kinase (p-Akt Ser473) were measured in pancreas by immunoblotting. The D&D treatment led to significant increase in p-Akt(Ser473), p-mTOR and Bcl-2 expression; decrease in Bax expression; and enhanced the production of intracelluar insulin in pancreas. In addition, D&D treated diabetic rats were compensated for body weight loss and alleviated hyperglycemia. These results suggest that the supplementation of D&D improves diabetes by inhibiting oxidative stress and ameliorating STZ-induced pancreatic damage through AKT/mTOR mechanism. Accordingly, the results strongly support that the D&D is beneficial in the treatment of T1DM by regenerating beta-cells against pancreatic dysfunction.