Aim This study was designed to explore the characteristics of VSMCs phenotype during aging and hypertension, and how miR-143/145 were influenced. Methods Mesenteric arteries from 1-, 3-, 9-, and 16-month-old WKY and SHR were isolated, artery histology were evaluated by staining with HE. VSMCs phenotype marker including α-actin, Calponin, and OPN were measured. miR-143/145 were quantified by real-time PCR. Results VSMCs contractile marker α-actin and Calponin expression both reached the peak at 3M and then decreased, while OPN increased with age in SHR with no obvious changes in WKY. The expressions of α-actin, Calponin, and OPN showed significant differences between SHR and the age-matched WKY. miR-143/145 firstly increased with age and then decreased in both WKY and SHR, and miR-143/145 in WKY-3M was significantly higher than the age-matched SHR. Conclusion Aging and hypertension accelerate the VSMCs phenotype switching in arterioles, promoting the synthesis phenotype; miR-143/145 is inversely regulated with contractile VSMCs and could play a role during aging hypertension.