Pulmonary arterial hypertension is a kind of intractable disease which threatens human health severely. The results of operation are unsatisfactory. Clinical drug therapy is the major treatment which aims to relieve symptoms, improve the quality of life, and prevent the disease from progressing. Over the last several years, the studies of stem cells provide a new direction for the treatment of pulmonary arterial hypertension. It's demonstrated that the therapeutic effects of stem cells are better than that of the traditional methods. With the deepening of the researches, the therapy of stem cells is more and more compelling. The therapy of stem cells for pulmonary arterial hypertension is reviewed in this paper.