AIM:To investigate the expression and pathological factorsof Angiopoietin-2 (Ang-2) in primary gastric cancers andadjacent normal tissues.METHODS:The expression of Angiopoietin-2 and VEGFwere studied in 72 primary gastric cancers and adjacentnormal tissues from the same patients by semi-quantitativereverse transcriptase-polymerase chain reaction (RT-PCR)and immumohistochemistry.RESULTS:Ang-2 was mainly expression in tumor cells.There were significantly difference between expression ofAng-2 in primary gastric cancer and in adjacent normaltissue samples (P=0.003).It was statistically correlationbetween Ang-2 and VEGF expression in tumors (P=0.0055).With regard to Ang-2 expression in tumors,there weresignificant difference between early stage and advancedstage (P=0.017),and significant difference between positivevascular involvement and negative vascular involvement(P=0.032).However,there was no significant differencebetween moderate-poor differential type and highdifferential type (P=0.908),between positive lymph nodemetastasis and negative lymph node metastasis (P=0.752),between positive serosal invasion and negative serosalinvasion (P=0.764).The cases with expression of Ang-2 wereincreasing with advanced stage and vascular involvement.CONCLUSION:The results manifested that Angiopoietin-2,coordinated with VEGF,play role in regulating tumorangiogenesis of gastric cancer. AIM: To investigate the expression and pathological factors of Angiopoietin-2 (Ang-2) in primary gastric cancers and adjacent normal tissues. METHODS: The expression of Angiopoietin-2 and VEGF were studied in 72 primary gastric cancers and adjacent normal tissues from the same patients by semi -quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immumohistochemistry .RESULTS: Ang-2 was mainly expression in tumor cells. Where were significantly difference between expression of Ang-2 in primary gastric cancer and in adjacent normal tissue samples (P = 0.003) .It was statistically correlated between Ang-2 and VEGF expression in tumors (P = 0.0055) .With regard to Ang-2 expression in tumors, there weresignificant difference between early stage and advanced stage (P = 0.017) negative vascular involvement (P = 0.032) .However, there was no significant difference between moderate-poor differential type and high differential type (P = 0.9 08), between positive lymph node metastasis and negative lymph node metastasis (P = 0.752), between positive serosal invasion and negative serosalinvasion (P = 0.764). The cases with expression of Ang-2 were reinforced with advanced stage and vascular involvement. results manifested that Angiopoietin-2, coordinated with VEGF, play role in regulating tumorangiogenesis of gastric cancer.