To explore the relationship between inactivation of TGF-beta signaling pathway and acute leukemia, the expressions of TGF-beta1, TbetaRII and c-myc in the bone marrow mononuclear cells were detected by S-P immunocytochemical staining. The results showed that no significant difference of TGF-beta1 exepression was found between the patients and the control (P > 0.05), the expression of TbetaRII was significantly lower in patients than in control (P < 0.05) and the expression of c-myc was significantly higher in patients than in control (P < 0.05). There was no significant difference of TGF-beta1, TbetaRII and c-myc exepression between acute nonlymphoid leukemia and acute lymphoid leukemia (P > 0.05). Expressions of TbetaRII and c-myc were negatively correlated (r = -0.474, P < 0.01). In conclusion, the leukemic cells escape from the growth inhibitory effect because of the inactivation of TGF-beta signaling pathway; downregulation of TGF-beta receptor II cause c-myc overexepression and leukemogenesis.