It's difficult to extract the target boundary using the region-based active contour models,for the interference of the image background when dealing with the medical target segmentation.An improved model of adapted LFI is proposed to solve this problem.The model constructs local fitting images to approach the initial image,and introduces the attractive factor to restrain curve evolution equation and well resume the curve gradualist,thus targets the image segmentation.The binary level set is employed to the whole segmentation process,which can avoid the numerical instability by the traditional level set.The application results show that the proposed method can segment the required target effectively and rapidly from medical images.