With argon laser coupled to a fiberoptic system, we carried out experimental studies to establish the optimal conditions in improving obstructive arterial disease without any complications of the arterial wall.This study was performed on human cadaveric aorta under air, blood and saline medium by using the bare-ended probe and the metal tip probe (0.7mm in diameter, 300μm core silica fiber).First of all, the craters in the aortic wall created by laser irradiation were microscopically examined, and the depth of each crater was precisely measured. Subsequently it could be considered that 6watts in laser output and 3 seconds in irradiation time were optimal conditions in one radiation for laser ablation using the metal tip probe.On the other hand, we also tried laser coronary angioplasty by using human cadaveric heart, and could get the coronary recanalization by repeated laser ablations (6w, 3sec, 7times).But many kinds of degrees of sclerotic changes were surely recognized on the arterial wall among them. So selective applications of the metal tip probe or the bare-ended probe and both of them was very important for excellent laser ablation.In addition, angioscopy was useful procedure to observe intravascular laser effects without arterial injuries. In conclusion, laser angioplasty under angioscopic guidance should be recommended from standpoints of its safety.