The modern researches on physiology verify that there are close relationships between central nervous system (CNS) and autonomic nervous system (ANS) and some autonomic functions can be regulated by CNS to some extent. In this paper, the mechanisms of cardiovascular system, especially of BP regulation, under CNS control are researched. A blood circulatory system dynamic model is established and applied practically to treatment of hypertensives trained with biofeedback technique, in which pulse transit time (PTT) is employed as an indirect index of BP change. The result shows that the curative effect of this method is efficient for BP control.