Most of the current palm vein recognition systems use the center of pa lm as the region of interesting(ROI),while troubled with the fuzziness of palm v ein on p alm center area,consequently influencing the performance of the system.To solve this problem,this paper performs medical analysis and contra st experiment of light absorption in the three areas on the palm:the center area of palm,the thenar area and the hypoth enar area.The thenar area is selected as the main scope of ROI.According to this result,a location method is proposed based on the thenar area.The method finds two stable characteristic points and squares the R OI with these two points.In the self-built palm vein database with 100distinct subjects,this study conducts im age definition experiment and abundance experiment on ROI extracted by this method and traditional method firs tly.The result of palm information in the thenar area is clearer and richer than that in the center of the palm.Finally,recognition experiments on the thenar ROI and the center of palm ROI are done.The results s how that the thenar ROI enhances the recognition performance.In conclusion,the thenar area is s uitabl e for ROI and the proposed method enhances the performance of palm vein recognition significantly.