Abstract: Previous edge-based image interpolation algorithm could not improve the medium and low-frequency texture details of interpolated image effectively. To preserve the texture-rich information, an image interpolation approach based on edge detection of fractional differential was studied and proposed. The fractional differential operator mask, which can extract medium and low-frequency texture detail effectively, was designed and realized on the basis of fractional differential theory. Then the measures of linear interpolation, quadratic interpolation and bilinear interpolation were used for those pixel points to be interpolated along edge directions, perpendicular to edge directions and in smooth areas, respectively. To evaluate the interpolated image quality, the indexes of peak signal to noise ratio (PSNR) and information entropy were used. The quantitative analysis and experimental verification of the proposed approach were implemented. The results show that this method could obtain texture-rich image information, increase the peak signal to noise ratio and satisfy the human visual sense.