Objective To study the expansion behavior of stent in stenotic vascular, in stent blood flow and fatigue life of stent by finite element method. Methods ANSYS was used to simulate the expansion of stent in stenotic vascular. The blood flow model was created by constructing the entities based on deformation of the related nodes from the result of dilation process. A sample model was also built to simulate the in stent blood flow. Stent fatigue life was evaluated based on Goodman’s method and accumulated damage method, respectively. Results (1) Plastic deformation appeared on most parts of struts. The major stresses were localized in the corner of the slots. (2) Turbulent flow occured near the stent. Stresses of stent in cross section of bridge struts along the direction of blood flow were highest. (3) Goodman’s method showed that the stent was safe, and cumulative damage indicated that the largest cumulative damage occured in the second cross section of bridge struts. Conclusions Finite element method can be effectively used to simulate the stent expansion, in stent blood flow and stent fatigue life.