According to features that the offshore sea has a smaller thermal capacity and shallow depth,a one-dimension model based on the balance of energy was used in the simulation of the mean annual SST of the East China Sea.The simulated results are consistent with the observation,and the feature of SST's variation as a function of latitude(longitude)is well reproduced.At the same time,the ability of simulating the SST's interannual variability of the model was examed.At last,the advantages and disadvantages of the simple model used on the shelf sea is analyzed.