The purpose of this study is to determine whether umbilical cord Mesenchymal Stem Cells of treatment for ulcerative colitis is safe and effective.

Ulcerative colitis is characterized as chronic and nonspecific inflammation of gastroenteritis tract．Nowadays，etiology and pathogenesis of UC have been unclear．Recent basic research has been revealed that stem cell can settle down in epithelium of gastroenteritis tract，which provide a hope for treating the disease.We hope umbilical cord Mesenchymal Stem Cells could not only address the need for epithelial cell replacement but also control of the autoimmune response to mocous membrane of colon.

Inclusion Criteria:

• Male or female, 18 years of age or older.
• Ulcerative colitis described according to usual criteria.
• Refractoriness Ulcerative colitis or unefficient by using other therapy
• Signed informed consent form.

Exclusion Criteria:

• History of neoplasm or hematological disease
• Uncontrolled high blood pressure (>180/110)
• Severe cardiac insufficiency (New York Heart Association [NYHA] IV) or ejection fraction<30%
• Malignant ventricular arrythmia
• Deep venous thrombosis during the last 3 months
• Active bacterial infection
• Body mass index > 35 Kg/m2
• Stroke or myocardial infarction during the last 3 months