Abstract.Statins have recently come under evaluation for the treatment of pulmonary arterial hypertension (PAH). The aim of this study was to examine the effects of atorvastatin on the clinical manifestations and expression of p38, p27 and Jab1 using a rat PAH model. Ninety-six male Wistar rats were divided into control (receiving no surgical treatment), vehicle and treatment groups, among which the last two groups underwent left pneumonectomy and were then treated with monocrotaline (MCT, 60 mg/kg). Both control and vehicle groups subsequently received saline, and the treatment group received atorvastatin (20 mg/kg) by stomach catheter. Rats were sacrificed, and mean pulmonary arterial pressure (mPAP) and right ventricle hypertrophy index (RVHI) were measured.The expression of p38, p27, and Jab1 was evaluated by immunohistochemistry and Western blotting. At 28 days, mPAP and RVHI and expression levels of Jab1 and p38 in the vehicle group were significantly higher than those in the treatment and control groups. However, the expression of p27 was lowest in the vehicle group among the three groups. Atorvastatin reduced PAP and RVHI in the rat PAH model, decreased expression of p38 and Jab1 but increased expression of p27.