Aim To establish a RT-PCR method for detecting expression of mRNA for inositol trisphosphate receptor (IP 3R) and to investigate expression of IP 3R subtypes in rat brain, myocardium and cultured vascular smooth muscle cells (VSMC). Methods Total RNA was isolated from different tissue of rat and was reversibly transcripted into cDNA. RT-PCR was performed with β-actin as internal label. Three oligonuclotide primers for each subtype of IP 3R were employed to amplify predicted DNA. Results It was found that all subtypes of IP 3R were expressed in cultured SMC. DNA sequencing indicated that amplified products of IP 3R Ⅱ subtype was identical to reported sequence from gene bank. Conclusion Our results suggested that RT-PCR established by us can be used as a reliable method for investigating expression of mRNA for IP 3R subtypes.