Recent research indicates that TGF-beta and type II receptor (TbetaR-II) play an important role in the pathogenesis of tumor. A high frequency of abnormalities in TbetaR-II has been demonstrated in various cancers. To identify the mutation of TbetaR-II in patients with acute leukemia, the bone marrow samples from 6 patients with acute leukemia and 11 normal individuals as control were detected by long-range RT-PCR. To detect a deletion in sequence of the TbetaR-IIgene, the PCR products were cloned to T vector and then sequenced. The results showed that there was existance of the isoform of TbetaR-II in 2 cases out of 6 patients with acute leukemia. These two patients had more poor prognosis than others. In conclusion, there was the isoform of TbetaR-II in partial patients with acute leukemia, and the isoform may be related with prognosis.