Abstract: Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) refer to a group of relatively rare and heterogeneous tumors. The treatment and prognosis are distinct for GEP-NENs of different genetic phenotypes, differentiation degree, pathological categories, staging and grading, clinical characteristics. Neoadjuvant therapy is becoming increasingly accepted in the compre-hensive treatment of GEP-NENs. More and more researches show that neoadjuvant therapy contri-butes to improve R₀ resection rate and eliminate metastasis of malignancies. However, the value of neoadjuvant therapy and whether it improves overall survival of GEP-NENs patients remain contro-versial. The principle of neoadjuvant therapy is to bring survival benefits for selective patients treated by optimal therapy at appropriate time. It is important to master certain degrees for above event nodes. Whether the neoadjuvant /conversion therapy serve as castle in the air or Noah's ark for GEP-NENs requires prospective randomized controlled tests to answer. Combined with guidelines at home and abroad, the authors systematically review the evidence based medicines on neoadju-vant and conversion therapy for GEP-NENs, demonstrate relative research progress, carry an indepth discussion on hot and difficult subjects and controversial issues, aiming to provide references for individualized, precised and standardized comprehensive treatment of GEP-NENs.