Aim To establish a model of vascular calcification in SD rats and observe the role of testosterone in aortic calcification. Methods 10-week-old SD male rats were divided into control group, calcification group, calcification+low-dose testosterone group, calcification+high-dose testosterone group, with 8 rats in each group. In addition to the control group, the other three groups were induced with vascular calcification in rats by vitamin D3 (300 kU/kg intramuscular injection) and nicotine (25 mg/kg dissolved in peanut oil in the morning and evening); The rats were injected 1 mg/kg exogenous testosterone (once every other day) in low-dose testosterone group, 2 mg/kg testosterone (once every other day) in high testosterone group, and sacrificed after 2 months. The serum testosterone and bone morphogenetic protein 4 (BMP-4) levels were determined by ELISA method. The calcium and alkaline phosphatase (ALP) contents in vascular tissues were detected by kit. The protein expression levels of BMP-4 and osteopontin (OPN) in aortic vascular tissues were detected by Western blot. Von Kossa staining was used to observe vascular calcification. Results (1) The model of vascular calcification in rats was successfully prepared:Von Kossa staining showed a large amount of black granule-like calcium deposits in the vascular media of rats in the calcified group, while the vascular structure of the control group was intact and no black calcium deposits were observed. (2) Effects of testosterone on vascular calcification:calcium content, ALP, BMP-4, OPN levels were significantly lower in the testosterone group than those in the calcification group (P<0.01), lower in the high-dose testosterone group than in the low-dose testosterone group, and the lowest in the control group; Von Kossa staining showed a large amount of black granular calcium deposits in the vascular media of the calcification group, while a small amount of calcium salt deposits in the low-dose testosterone group and the high-dose testosterone group, and no calcium salt deposits in the control group. Conclusion Exogenous testosterone can alleviate vascular calcification induced by vitamin D3 and nicotine in rats to some extent.