Based on the combination of the adjacent diffusion method and the selective smoothing filter,a new anisotropic diffusion algorithm for image enlargement is proposed,which is called as the adjacent diffusion and selective smoothing algorithm(ADASS).Compared with other methods,ADASS is less complex,and moreover,with its characteristic of reducing noise and enhancing edges simultaneously,the higher quality of an enlarged image can be obtained both on edges and in smooth area.The experimental results and PSNR value verify the validity of the proposed algorithm.