The PKC family has been implicated in a wide range of biological response in a number of different cellular systems. Although the functions of PKC have been vigorously studied using pharmacological tools, there is little information about the expression pattern of its isoforms in human bronchial smooth muscle cells (hBSMCs). In the present study, RT-PCR and immunoblot analyses were carried out to detect all the PKC isoforms expressed in cultured normal hBSMCs. The RT-PCR analyses revealed that mRNAs of the known PKC isoforms except for PKCγ and θ were detected in the hBSMCs. Among them, protein expressions of the isoforms except for PKCη and μ were also detected by immunoblottings. Thus, the present study clearly demonstrated the expression of multiple PKC isoforms, i.e., PKCα, β, δ, ε, ζ and ι in hBSMCs.