Esophageal cancer is one of the common malignant tumors, and the mortality rate ranks fourth among all malignant tumors in China. Radiotherapy is one of the main methods for the treatment of esophageal cancer, and radiation resistance is one of the important factors of tumor recurrence and metastasis. Therefore, the study of radioresistance related markers of esophageal cancer is of great significance to improve the radiosensitivity of esophageal cancer. We used microarrays to detail to find critical prognostic factors for esophageal cancer patients after radiotherapy. Overall design: We screened out the differential genes before and after radiotherapy by expression microarray: select the tissue samples of the same patient before and after radiotherapy (radiotherapy to 40Gy, gastroscopy pathology, pathological report found squamous cell carcinoma), a total of 4 pairs of samples, a total of 8 cases. The samples were grouped and divided into pre-radiotherapy and post-radiotherapy.