Character recognition of license plate is an important component of an intelligent license plate recognition system. Both the number of categories and the complexity of background of license plate character affected the correct recognition rate. A character recognition method of license plate based on Convolution Neural Network (CNN) was proposed for improving the correct recognition rate. Firstly, the simple shape structures of license plate characters were obtained through image preprocessing which included image size normalization, image denoising, image binarization, image thinning, and character centering. Secondly, the preprocessed character images were trained and recognized by the proposed CNN model. The experimental results show that the correct recognition rate of the proposed method can reach 99.96%, which is better than the other three compared methods. It is demonstrated that the proposed CNN method has good recognition performance for the license plate character, and can meet the practical application requirements.