Abstract: The quality problem of head width narrow appears on one hot rolled strip line sometime. In order to using the real data,in this paper the dynamic time warping was firstly utilized to transfer the different length data to the same length,and then the feature selection method based on information entropy was applied to analyze the order of important about process parameters that effect on the quality. The first several process parameters were selected as the causes of head width narrow of hot rolled strip. The results show that the feature selection method based on information entropy can track the causes of the head width narrow of hot rolled strip effectively to adjust the process. In the future,the methods can be applied in other quality diagnosis,other processes or other application fields.