Aim To explore the modification of inositol 1,4,5-trisphosphate receptor type Ⅰ(IP3RⅠ) expression by calcineurin in calcification of vascular smooth muscle cells. Methods Rat aortic vascular smooth muscle cells after subculture were randomly divided into control group,calcification group and cyclosporine A(CsA) group.Rat aortic vascular smooth muscle cell calcification model was constructed by NaH2PO4.Expression of IP3RⅠand calcineurin was determined by RT-PCR and Western blot methods.Alkaline phosphatase(ALP) Activity and Ca2+ concentration were determined by colorimetric method.CaN activity was determined by ELISA. Results Expressions of IP3RⅠand CaNB mRNA and protein increased in calcification group compared with control group(P<0.01).Expressions of IP3RⅠand CaNB mRNA and protein decreased in CsA group compared with calcification group(P<0.01).Ca2+ concentration and CaN and ALP activities of rat aortic smooth muscle cells increased in calcification group compared with control group(P<0.01).ALP activity and Ca2+ concentration increased in CsA group compared with calcification group(P<0.05 or P<0.01).CaN activity decreased in CsA group compared with calcification group(P<0.01). Conclusions CaN can enhance the expression of IP3RⅠmRNA and protein in cell calcification.