It has been recognized for many years that adenosine and adenosine 5'-monophosphat (AMP),adenosine 5'-diphosphate(ADP)and adenosine 5'-triphosphat(ATP)are potent vasoactive substances.In this paper,it was demonstrated that ATP,ADP induced endothelium dependent relaxation on isolated porcine coronary arterial rings but adenosine produced endothelium-independent relexation on aboveprepations.It was also observed with MTT colorimetric assay that AMP,ADP and ATP inhibited proliferetion of porcine aortic smooth muscles in dose-dependent manner, similar to adenosine. The results suggest that purine nucleoside adenoside and its analogues act as growth regulators of vascular smooth muscle cells. In addition,the clinical application of adenosine drugs was discussed in detail.