Sea level variability in the East China Sea (ECS) was examined based primarily on the analysis of TOPEX/Poseidon altimetry data and tide gauge data as well as numerical simulation with the Princeton ocean model (POM). It is concluded that the inter-annual sea level variation in the ECS is negatively correlated with the ENSO index, and that the impact is more apparent in the southern area than in the northern area. Both data analysis and numerical model results also show that the sea level was lower during the typical El Nio period of 1997 to 1998. El Nio also causes the decrease of the annual sea level variation range in the ECS. This phenomenon is especially evident in the southern ECS. The impacts of wind stress and ocean circulation on the sea level variation in the ECS are also discussed in this paper. It is found that the wind stress most strongly affecting the sea level was in the directions of 70o and 20o south of east, respectively, over the northern and southern areas of the ECS. The northwest wind is particularly strong when El Nio occurs, and sea water is transported southeastward, which lowers the sea level in the southern ECS. The sea level variation in the southern ECS is also significantly affected by the strengthening of the Kuroshio. During the strengthening period of the Kuroshio, the sea level in the ECS usually drops, while the sea level rises when the Kuroshio weakens. Sea level variability in the East China Sea (ECS) was classified based on the analysis of TOPEX / Poseidon altimetry data and tide gauge data as well as numerical simulation with the Princeton ocean model (POM). It is said that the inter-annual sea ​​level variation in the ECS is negatively correlated with the ENSO index, and that the impact is more apparent in the southern area than in the northern area. Both data analysis and numerical model results also show that the sea level was lower during the typical El Nio period of 1997 to 1998. El Nio also causes the decrease of the annual sea level variation range in the ECS. This phenomenon is particularly evident in the southern ECS. The impacts of wind stress and ocean circulation on the sea level variation in the ECS are also discussed in this paper. It is found that the wind stress most stronglyumo the sea level was in the directions of 70o and 20o south of east, respectively, over the northern and southern areas of the ECS. The northwest wind is particularly strong when El Nio occurs, and sea water is transported southeastward, which lowers the sea level in the southern ECS. The sea level variation in the southern ECS is also significantly affected by the strengthening of the During the strengthening period of the Kuroshio, the sea level in the ECS usually drops, while the sea level rises when the Kuroshio weakens.