In leukemia patients, T-cell function has been suppressed with the disease progress. Patients with chronic lymphocytic leukemia (CLL) are all to a degree immunodeficient. In order to elucidate the feature of T-cell receptor signal transduction in CLL, the expression levels of CD3γ, δ, ε, and ζ chain, FcεRIγ, and Zap-70 genes in peripheral blood mononuclear cells (PBMCs) were analyzed. Real-time polymerase chain reaction with SYBR Green technique was used for detecting the gene expression level in PBMCs from 13 patients with CLL, 13 healthy individuals, and 10 B-cell acute lymphocytic leukemia (B-ALL) served as control. The β2-microglobulin gene was used as an endogenous reference. Relative mRNA expression level of genes was analyzed by using the 2(-ΔCt) × 100% method. Significant lower expression levels of CD3γ, ε, and ζ chain genes, as well as FcεRIγ gene were found in CLL samples. Moreover, there was lost the negative correlation of the expression levels between CD3ζ and FcεRIγ genes. The expression level of Zap-70 in CLL was lower than those from healthy controls, while higher than those from B-ALL group. There was no significant correlation between the expression levels of CD3ζ and Zap-70 genes neither in the healthy group nor in the CLL group. In conclusion, the results provide a global gene expression profile of CD3γ, δ, ε, and ζ chains, and the CD3ζ-related genes FcεRIγ and Zap-70 in CLL. Deficiency of these gene expression levels might represent the feature related to T-cell immunodeficiency. The study might contribute to better understand the cellular immune features in CLL patients.