The present invention relates to a saxatilin derivative having an increased half life and a use thereof. The saxatilin derivative of the present invention has thrombolytic ability similar to that of saxatilin, which is the mother protein, a remarkably increased protein half life, and efficiently dissolves, for long period of time, blood clots already formed in blood vessels of an animal model with a FeCl3-induced carotid by using the same. Therefore, a composition containing, as an active ingredient, the saxatilin derivative of the present invention does not cause reocclusion after penetration and effectively opens to microvessels, and is thus very useful for treating angiostenosis or occlusive diseases (for example, cerebrovascular diseases, cardiovascular diseases, arteriosclerotic vascular diseases, coronary artery diseases, and peripheral vascular diseases).