This prospective randomized controlled clinical Trial will be performed in patients with locally advanced squamous cell carcinoma of the head and neck. The objectives of the trial are to compare the efficacy and safety of Capecitabine treatment with placebo as adjuvant therapy to patients who have received radiotherapy.

Inclusion Criteria:

1. histologically type： squamous cell carcinoma
2. head and neck squamous cell carcinoma (HNSCC), Tumor staged as III to IVb (according to the 8th AJCC edition).
3. Eastern cooperative oncology group (ECOG) performance status 0 or 1
4. Age between 18 and 65 years old
5. Prior treatment with chemo-radiotherapy (CRT) based Platinum drugs.
6. Adequate marrow: WBC count ≥4000/μL, hemoglobin ≥90g/L and platelet count ≥100000/μL.
7. Normal liver function test: Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST) ≤ 1.5×upper limit of normal (ULN) concomitant with alkaline phosphatase (ALP) ≤ 2.5×ULN, and bilirubin ≤ 1.5ULN.
8. Adequate renal function: creatinine clearance ≥60 ml/min.
9. Patients must be informed of the investigational nature of this study and give written informed consent.

Exclusion Criteria:

1. Nasopharyngeal carcinoma and/or salivary gland carcinoma.
2. Any other malignancy (except for primaries, appropriately treated superficial basal cell skin cancer and surgically cured cervical cancer in situ)
3. currently recurrent of metastatic disease
4. received research drug in 4 weeks
5. Prior treatment with epidermal growth factor receptor (EGFR)-targeted small molecules, EGFR-targeted antibodies, and/or any investigational agents for HNSCC
6. Severe hematological abnormality and intolerance to chemotherapy
7. Evidence of significant medical illness that in the investigator's judgment will substantially increase the risk associated with the subject's participation in and completion of the study.
8. Pregnancy or breast feeding
9. patients who cannot obey to completion of the study