Aim To investigate the association between serum bone morphogenetic protein-2 (BMP-2), bone morphogenetic protein-4 (BMP-4) levels and the severity of vascular calcification in CKD rat model. Methods Fifty-five SD rats were randomly divided into control group (n＝20) and CKD group (n＝35). The rats were sacrificed at 2,4, 6,8 week respectively. The kidney and aortic pathologies were analyzed. Blood biochemical indicators, serum BMP-2 and BMP-4 levels, and aortic calcium content were determined. The expression levels of BMP-2, BMP-4 were examined by immunohistochemistry. Results Compared with control group, the CKD rats exhibited a significantly increase in 24 h urinary protein, serum urea nitrogen, creatinine and cystatin C (P＜0.05). Kidney HE staining showed that renal tubular expansion began to emerge since the second week, accompanying with brown yellow substance deposition, interstitial fibrosis, glomerular partial atrophy, and inflammatory cells infiltration. Alizarin red staining showed massive granular deposition and formation of calcified nodules in aorta at the 8th week. The aortic calcium content was significantly increased, which was positively correlated with serum BMP-2 (r＝0.929, P＜0.01) and serum BMP-4 (r＝0.702, P＜0.01) levels in CKD rats. The expression of BMP-2 and BMP-4 in aorta increased significantly after successful establishment of the model at the fourth week. Conclusion Elevated serum BMP-2 and BMP-4 levels may serve as serum markers for CKD vascular calcification.