There have been marked advances in clinical and histological aspects GEPNET: gastroenteropancreatic neuroendocrine tumor. In particular, histopathological classification of GEPNET based on WHO 2010 devided the tumor into three histological grades, neuroendocrine tumor(NET)G1, G2 and neuroendocrine carcinoma(NEC), exclusively based upon the status of tumor cell proliferation determined by mitotic counts and/or the Ki67 labeling index. The clinical management of patients with GEPNET must be determined by TNM and the WHO 2010 classifications. The classifications were proposed based upon the evidences of several clinical studies, and it is therefore crucial for clinicians to understand the new classifications, for the clinical management of NET patients.