Abstract: AIM To observe the changes of microRNA195 and Bcl-2 / Bax protein in rat aortic calcification. METHODS Rats were randomly divided into two groups: control group( n = 8) and calcification group( n = 8). Rats in the calcification group received a single-dose I. M. injection of vitamin D3( 300 000 U / kg) in the morning and two doses of nicotine( 25 mg / kg dissolved in peanut oil) by gavage,one in the morning and one in the evening to induce vascular calcification. Rats in the control group were treated with the same amount of normal saline. After a 6-week intervention,morphologic changes of arteries were examined by Von Kossa staining,expressions of Bcl-2 / Bax were detected by immunohistochemistry and confirmed by Western blot,and expression of miRNA-195 was measured by quantitative real-time PCR( qRT-PCR). RESULTS Mass black granules were seen deposited in the calcified vascular vessels in calcification group. No obvious difference was found in expression of Bax,but the expression of Bcl-2protein was significantly upregulated in the calcification group( P < 0. 05). The level of miRNA-195 in the calcification group was significantly higher than in the control group( P < 0. 01). A positive correlation between the levels of miRNA-195 and Bcl-2 protein was observed( r = 0. 791,P < 0. 05). CONCLUSION Level of miRNA-195 is upregulated along with the increasing expression of Bcl-2 protein in vascular calcification. miRNA-195 and Bcl-2 protein may be involved in vascular calcification.