Abstract: Objective: Establishing a kind of convenient and effective method to isolate and purify islets in order to decrease injury and obtain islets with high quality. Methods: Pancreas of SD rats were perfused with collagenase through choledochus, then the pancreas were isolated and digested. Lymphocyte （Histopaque-1077） was used to purify the digested pancreas. Results: This method could obtain a large number of rat iselets with purity ＞95%. The isolated islets had a correct response upon glucose stimulation in vitro. When the iselets were transplanted into diabetic mice the high blood glucose level could be decreased. Conclusion: Using lymphocyte to purify islets of rat is a kind of convenient, effective, cheap, and repeatable method.