PURPOSE: This study was designed to examine the reliability and easy applicability of new version of UICC-TNM classification (UICC, 1997) compared with old version of UICC-TNM classification (UICC, 1992) and JRSGC (Japanese Research Society for Gastric Cancer) classification of gastric cancer. MATERIALS AND METHODS: For 1043 patients who underwent curative resection from Jan. 1992 to Dec. 1996 in Korea Cancer Center (KCCH), old version of UICC-TMN classification and JRSGC classification were compared with the new version of UICC-TNM classification. RESULTS: Correlation coefficient between topographic classification (old UICC-TNM, JRSGC) of lymph node and numeric classification was 0.9 (p<0.05). 5-year survival rates according to old UICC, TRSGC, new UICC classification were 94.9% at stage Ia; 96.6, 96.5, 97.1% at stage Ib; 73.8, 73.8, 73.0% at stage II; 54.1, 55.8, 58.0% at stage IIIa; 35.5, 42.0, 36.0% at stage IIlb; 25.9, 22.3, 23.9% at stage IV. 5-year survival rates of each classification had significant difference among stages (p<0.0001), but there was no significant difference among each classification. CONCLUSION: The new version of UICC-TNM classification based on the number of involved lymph nodes allows a staging system as reliable as the old version of UICC-TNM and JRSGC classification. In addition, the new version of UICC-TNM classification can be applied without methodologic problems and seems more convenient and reproducible.