In order to make an objective assessment of the effect of the Lightning N owc asting and Warning System (which is developed by the Chinese Academy of Meteorol ogic al Sciences, CAMS_LNWS), the evaluation method of CAMS_LNWS products has been studied and a software has been developed by the Laboratory of Lightn ing Physics and Protect ion Engineering. Three indicators, POD (Probability of Detection), FAR (False Al arm Rate) and TS (Threat Score) are used in the evaluation method. They not only can assess the forecast effect of CAMS_LNWS products, but also can guide the im p roving of lightning nowcasting and warning methods partially. Owing to the reasonable design, comprehensive functions, easytouse interface an d rich products, the assessment software can meet the needs for evalution of ligh tning operational products.