Objective To clarify the effect and mechanisms of astaxanthin on the calcification of aortic valve interstitial cells （VICs） induced by osteogenic medium （OM）. Methods The CCK-8 assay was used to analyze the effects of different concentrations of astaxanthin on the proliferation of VICs. After treating VICs with astaxanthin in OM, Alizarin Red staining was performed to detect calcified nodules, and Western blotting was used to measure the expression levels of osteogenic differentiation markers ALP and Runx2. Additionally, Western blotting and immunofluorescence detection were utilized to assess the expression levels of Nrf2 and HO-1 proteins. The levels of intracellular reactive oxygen species （ROS） were measured by DCFH-DA fluorescence staining. Results The CCK-8 results indicated that the optimal concentration of astaxanthin for intervention was 25 μmol/L. Astaxanthin treatment reduced the formation of calcified nodules induced by OM in VICs, and inhibited the expression of osteogenic differentiation markers ALP and Runx2 （P<0.01）. Furthermore, Astaxanthin treatment decreased the expression levels of Nrf2 and HO-1 （P<0.01）, and reduced intracellular reactive oxygen species levels （P<0.01）. Conclusion Astaxanthin may mitigate oxidative stress and calcification in VICs by enhancing the Nrf2/HO-1 antioxidant signaling pathway.