PURPOSE: The purpose of this study was to revise the KPCS-1 and to standardize the three patient classification systems for general ward, ICU and NICU. The actual utilization of the KPCS-1 score and each nursing activity was evaluated and the relationships between KPCS-1 score and nursing related variables were reviewed. METHODS: The 47,711 KPCS-1 scores of 6,931 patients who discharged from 1st to 30th April 2017 were analyzed and the statistical significance between KPCS-1 score and nursing related variables was reviewed by Generalized Estimating Equation. The revision of the KPCS-1 was carried out by Partial Least Square model. The 3 patient classification systems (KPCS-1,KPCSC and KPCSN) were standardized by professional reviews. RESULTS: KPCS-1 was a valid instrument to express nursing condition adequately and was revised as a new version which has 34 nursing activity items. The names and terminologies of pre-existing 3 patient classification systems developed by KHNA were standardized as KPCS-GW, KPCS-ICU, KPCS-NICU. CONCLUSION: KPCS-1 was a valid instrument to represent diverse nursing conditions precisely and was revised as a 34-item KPCS-GW. The terminologies of the other patient classification systems by KHNA were standardized as KPCS-ICU and KPCS-NICU.