Will meet the inclusion criteria of patients with esophageal squamous cell carcinoma, divided into 2 groups randomly:

Experimental group: radiotherapy combined with S-1 chemotherapy.

Control group: radiotherapy combined with S-1 chemotherapy and cisplatin.

Will meet the inclusion criteria of patients with unresectable esophageal squamous cell carcinoma, divided into 2 groups randomly:

Experimental group: radiotherapy combined with S-1 chemotherapy;

control group: radiotherapy combined with S-1 chemotherapy for first to 14 days and 29 ~ 42 days, plus cisplatin first 1~ 4 days and 29 ~ 33 days. Using IMRT radiotherapy.

Two weeks after radiotherapy finish, two cycle adjuvant chemotherapy with S-1 70 mg/m2 1~ 14 days, or S-1 70 mg/m2 1~ 14 days, plus cisplatin 25mg/m2 1~ 4 days, 21 days for a cycle.

Primary Outcome Measure is complete remission rate.

Secondary Outcome Measures are overall survival (OS) and Progression-Free-Survival (PFS) and toxicity.

Inclusion Criteria:

1. Histology or cytology confirmed esophageal squamous cell carcinoma.
2. There are measurable lesions in the RECIST standard.
3. American Joint Committee on Cancer/Union Internationale Contre le Cancer esophageal cancer staging (Sixth Edition) clinical stage II a~ IV B period.
4. Age younger than 75 years old.
5. Eastern Cooperative Oncology Group physical status score was 0 ~ 1.
6. No esophageal perforation and active esophageal bleeding, no obvious trachea, thoracic major vascular invasion.
7. Chest chemotherapy and radiotherapy, immunotherapy or biologic therapy have not been performed before.
8. Serum hemoglobin is<100g/L, platelet>100 * 109/L,Absolute neutrophil count>1.5 * 109/L.
9. Cr≤1.25 upper normal limit or CCr≥60 mL/min.
10. Serum bilirubin ≤1.5 times upper normal limit, Aspartate transaminase (SGOT) and Alanine aminotransferase (SGPT) ≤ 2.5 times upper normal limit,Alkaline phosphatase≤ 5 times upper normal limit.
11. A history of interstitial pneumonia and interstitial pneumonia.
12. FEV1>0.8 liters.
13. Patients or family members signed a formal informed consent.

Exclusion Criteria:

1. Prior to the start of the trial had received thoracic radiotherapy, chemotherapy or surgical resection of esophageal cancer.
2. Primary lesions were multifocal esophageal cancer patients, the lower bound of esophageal primary lesions was less than 3cm.
3. Patients with severe cardiovascular or pulmonary disease, interstitial pneumonia or a history of interstitial pneumonia.
4. Patients with distant metastases.
5. There were obvious esophageal ulcer, chest and back with moderate pain, and the symptoms of esophageal perforation.
6. Can't understand the test requirements, or patients may not comply with the requirements of the test.
7. There are other malignant lesion patients, but can cure skin cancer (non melanoma), cervical carcinoma in situ or malignant disease cured except for more than 5 years.
8. An allergic reaction known to have 3 or 4 levels of any treatment.
9. Had participated in other clinical trials in the past 30 days.
10. The researchers believe that some of the obvious diseases that should be excluded from this study are excluded.