ObjectiveTo investigate the effect of secreted frizzled related protein 1（SFRP1） via Wnt/β-catenin signaling pathway on calcification of vascular smooth muscle cell. MethodsPrimary human aortic vascular smooth muscle cells were transfected with SFRP1-specific small interfering RNA （siSFRP1） to knock down SFRP1 expression， transfected with lentiviral vector Lenti-Sfrp1 to overexpress SFRP1， and stimulated with 3 mmol/L sodium dihydrogen phosphate （Pi） to establish a cellular vascular calcification model. In vivo， a mouse model of acute vascular calcification was established using vitamin D₃ （VD₃） treatment. The SFRP1 inhibitor WAY-316606 was administered intraperitoneally （0.5 mg/kg daily for 7 days）. Aortic calcification was quantified by micro-computed tomography （micro-CT）. Western blot analysis was performed to detect the expression of osteogenic differentiation markers （RUNX2 and BMP2）， vascular smooth muscle cell contractile marker SM22α， and β-catenin protein in the Wnt signaling pathway. The severity of vascular calcification was evaluated through calcium content measurement and Alizarin Red staining. These approaches were employed to investigate the effect of SFRP1 on VSMC calcification. ResultsIn the primary human vascular smooth muscle cell calcification model and the acute vascular calcification model， the expression of SFRP1 protein was significantly down-regulated （0.30±0.02， P = 0.02； 0.15±0.03， P = 0.04）. The expression of RUNX2 （2.91±0.38， P ＜ 0.05） was significantly up-regulated and SM22α （0.48±0.08， P ＜ 0.05） were significantly down-regulated by small interfering RNA （siRNA）， whereas the Wnt/β-catenin signaling pathway was also significantly activated （2.01±0.11， P = 0.003）. In vivo， inhibition of SFRP1 exacerbated aortic calcification and significantly up-regulated the expression of BMP2 （3.11±0.55， P = 0.04） and β-catenin （3.97±0.44， P = 0.03）. Lentiviral overexpression of SFRP1 significantly downregulated RUNX2 （1.34±0.04， P = 0.02） and β-catenin （1.06±0.06， P = 0.04） expression， while upregulating SM22α （0.74±0.03， P= 0.03）. Quantitative alizarin red staining and calcium content assays demonstrated that SFRP1 overexpression significantly inhibited vascular smooth muscle cell calcification （1.36±0.08， P=0.000 6；1.51±0.03，P=0.002 1）. ConclusionSFRP1 attenuates vascular smooth muscle cell calcification via the Wnt/β-catenin signaling pathway.