In order to evaluate the exposure dose of residents living near nuclear power plants, a Off-site Dose Calculation Program (ODCP) has been developed based on SAP since 2021. The ODCP consists of social environmental factor, atmospheric diffusion factors, liquid/gas dose evaluation, and comprehensive analysis, and was developed by dividing it into functional modules. The offsite dose calculation can be carried out monthly, quarterly, semi-annual, and annual, and resident dose evaluation is conducted by entering air diffusion factors and emissions for each period. It also enables comprehensive evaluation result management by developing history management functions together.