From September 2006, 92 patients with long bone delayed unions and nonunions were treated with percutaneous autologous bone marrow derived stem cells grafting and analyzed by myelogram and numering CD34( +) cells in Orthopaedic-Traumatology Department- VietDuc Hospital and Hematololy Department- 108 Hospital. The results showed that: - The mean number of nucleated cells in bone marrow was 54,1 +/- 23,9 GIL, as similar as those of normal individuals. The mean number of CD34( +) cells in bone marrow was 0,36 +/- 0,22 GIL, lower than normal individuals. - The mean number of nucleated cells was decreased significantly with age. - There were significant difference of the number of nucleated cells and CD34( +) cells between patients with and without infected history.