Cloud-radiative forcing (CRF) at the top of the atmosphere (TOA) over the west Pacific warm pool (WP) shows unique characteristics in response to El Ni?o events. In this region, the responses of CRF to El Ni?o events have been a useful metric for evaluating climate models. Satellite data are used to analyze the CRF anomalies to El Ni?o events simulated by the new and old versions of the Climate System Model of the Chinese Academy of Meteorological Sci-ences (CAMS-CSM), which has participated in the Atmospheric Model Intercomparison Project (AMIP). Here, simu-lations for super El Ni?o years, El Ni?o years, and normal years are compared with observations. The results show that the mean values of both longwave CRF (LWCRF) and shortwave CRF (SWCRF) in CAMS-CSM are weaker than the observations for each category of El Ni?o events. Compared with the old version of CAMS-CSM, the de-crease in LWCRF during El Ni?o events is well simulated by the new version of CAMS-CSM. However, both new and old models cannot reproduce the anomalous SWCRF in El Ni?o events. The biases in the CRF response to El Ni?o events are attributed to the biases in the cloud vertical structure because of a weaker crash of the Walker circu-lation in CAMS-CSM. Due to the modification of the conversion rate from cloud droplets to raindrops in the cumu-lus convection scheme, the new version of CAMS-CSM has better CRF skills in normal years, but biases in El Ni?o events still exist in the new version. Improving the response of the Walker circulation to El Ni?o events is key to higher skills in simulating the cloud radiative responses.