Background:　Gastroesophageal　Junction　neuroendocrine　neoplasms　(GEJ-NENs)　are　rare　and　heterogeneous　tumors.　We　aim　to　analyze　the　clinicopathlogical　features　and　prognostic　factors　of　GEJ-NENs　and　to　compare　the　outcome　of　GEJ-NENs　with　other　gastric　NENs.　Methods:　A　total　of　297　GET-NENs　patients　were　enrolled　from　10　Chinese　hospitals　and　3152　gastric　NENs　patients,　including　274　GEJ-NENs,　were　retrieved　from　Surveillance,　Epidemiology,　and　End　Results　(SEER)　database.　Results:　The　clinical　characteristics　of　GEJ-NENs　among　different　races　were　different.　All　Chinese　patients　had　GEJ-NENs　of　grade　3,　with　67.7%　of　poorly　differentiated　NEC　and　32.3%　of　MANEC.　In　SEER　database,　70.8%　of　white,　62.5%　of　black,　and　87.5%　of　AP　patients　had　poorly　differentiated/undifferentiated　tumors.　In　Cox　multivariate　analysis,　NEC/MANEC　(HR　2.09,　95%CI　1.24-3.56;　P　=　0.006),　lymph　node　metastasis　(HR　3.52,　95%CI　1.68-7.34;　P　=　0.001),　and　distant　metastases　(HR　3.90,　95%CI　2.50-6.08;　P　＜　0.001)　are　independent　predictors　of　overall　survival.　Surgical　resection　showed　a　median　OS　improvement　of　13.1-73.3　months　(HR　0.21,　95%　CI　0.14-0.33,　P　＜　0.001).　Adjuvant　therapy　did　not　improve　survival　for　postoperative　GEJ-NEN　patients　(P　=　0.141).　GEJ-NENs　were　larger,　higher　grade,　more　distant　metastasis,　and　worse　prognosis　than　other　gastric　NENs.　Conclusion:　GEJ-NENs　were　mostly　poorly　differentiated　carcinomas,　and　all　of　Chinese　patients　were　NEC/MANEC.　The　outcome　of　MANEC　was　preferable　to　NECs.　Both　lymph　nodes　metastasis　and　distant　disease　were　independent　predictors　of　prognosis.　Surgical　resection　can　improve　survival,　but　postoperative　adjuvant　therapy　had　no　additional　benefit.　GEJ-NENs　have　worse　survival　than　other　gastric　NENs.