Abstract: Objective To analyse the clinical effect of cotransplantation of haploidentical hematopoietic stem cells and umbilical cord mesenchymal stem cells (UC-MSCs) for patients with refractory/relapsed hematologic malignancy. Methods Clinical data about 87 patients with refractory/relapsed hematologic malignancy who underwent haploidentical hematologic stem cells transplantation (haplo-HSCT) at The First Affiliated Hospital of Chinese PLA General Hospital from January 2007 to December 2013 were summarized. The engraftment, graft-versus-host disease (GVHD), overall survival (OS), disease/progression-free survival (PFS) and relapse after 2 years were observed. Results All patients given MSCs showed sustained hematopoietic engraftment without any adverse UC-MSC infusion-related reaction. The median time of transplantation of neutrophil＞ 0.50×10⁹/L and platelet＞ 20×10⁹/L engraftment was 12.0 days (9-21 days) and 14.0 days (10-28 days), respectively. GradeⅡtoⅣandⅢtoⅣ aGVHD was observed in 30 of 87 (34.5%) patients and 16 of 87 (18.4%), respectively. Chronic GVHD was observed in 33 of 71 (46.5%) patients and was extensive in 8 patients (11.3%). The probability that patients would attain 2-years OS, PFS and relapse was 66.7%, 62.9% and 13.8%, respectively. During follow-up for 1 to 79 months, 59 cases (67.8%) survived and 28 cases died, 9 patients died as a result of infection, 11 patients of GVHD and 8 patients of relapse. Conclusion Cotransplantation of haploidentical hematopoietic stem cells and UC-MSCs has good treatment effect to refractory/relapsed hematologic malignancy, and also it is a good survival opportunity for high-risk patients.