To investigate the T cell distribution characters of TCR Vbeta repertoire in Ph(+) and Ph(-) CML. The 24 subfamilies of the TCR Vbeta genes were amplified in peripheral blood T cells from 13 patients with CML (Ph+ b3a2, 5 cases; Ph+ b2a2, 5 cases; Ph(-), 3 cases) by RT-PCR, to analyze the usage of Vbeta subfamilies in different CML patients. The results showed that the expression pattern of Vbeta repertoire was different in normal individuals and in patients with CML which only have part of Vbeta subfamily T cells. 4 - 16 (mean 10.2) Vbeta subfamily T cells were detected in the Ph+ b3a2 CML, 8 - 11 (mean 8.8) Vbeta subfamily T cells in the Ph(+) b2a2 CML and 5 - 6 (mean 5.7) in Ph(-) CML. Moreover, the expression of Vbeta subfamily T cells was different among these three types CML.Vbeta10 and Vbeta16 were detected in the all cases with Ph(+) b3a2 and Ph(+) b2a2 CML, whereas Vbeta9 and Vbeta22 could be found in the most cases with Ph(+) b3a2 CML or Vbeta24 and Vbeta8 in Ph(+) b2a2 CML. In patients with Ph(-) CML, Vbeta24 were detected in all samples, and Vbeta9, Vbeta10, Vbeta13 and Vbeta22 were found in the most cases. The results suggest that skew distribution of TCR Vbeta subfamily T cells was existed in peripheral blood of Ph(+) and Ph(-) CML patients. The selected usage of TCR Vbeta is different in various types of CML patients. It may relate to difference of CML cells associated antigen and individual special immunity reaction.