Burn trauma,especially extensive ones, remains a life-threatening local and general inflammatory condition destroying the skin and underlying tissues, and resulting in serious sequelae. Remarkable progress has been achieved during last 30 years，stem cell therapy plays an important role in this progress. Human umbilical cord mesenchymal stem cells (hUCMSCs) and human cord blood mononuclear cells (hCBMNCs) have been shown to have the ability to modulate the immune response and enhance angiogenesis, suggesting the novel and promising therapeutic strategy for burn. In this study, the safety and efficacy of hUCMSCs and hCBMNCs transplantation will be evaluated in patients with acute burn.

To investigate the safety and efficacy of human cord blood mononuclear cells and human umbilical cord mesenchymal stem cells transplantation in patients of Acute, Moderate-Severe, Full-thickness burn.

Inclusion Criteria:

• Between age 18- 65 years, both gender.
• Diagnosed with Acute, Moderate-Severe, full-thickness burn:

Burn occurring within the 72 hours prior to administration. TBSA 20-55%, third degree wounds surface area < 19 % ;

• Willing to sign the Informed Consent Form.

Exclusion Criteria:

• All other burns except thermal origin.
• Chronically malnourished, poor medical condition or shock
• Systemic inflammatory response syndrome (SIRS) or septicopyemia
• Moderate-severe inhalation injury airways to lung
• HIV+
• Autoimmune disease, e.g. lupus erythematosus, multiple sclerosis.
• Severe pulmonary and hematological disease, malignancy or hypo-immunity.
• Currently undertaking other treatment that may affect the safety/efficacy of stem cells.
• Pregnancy or lactation
• Enrollment in other trials in the last 3 months.
• Other criteria the investigator consider improper for inclusion.