Abstract: It is a difficult problem that maintains the image texture details and edge structure simultaneously in image interpolation technology. To overcome this problem, a new method of image interpolation based on parameter optimization is proposed. First, a new type of C² continuous rational interpolation with adjustable parameters is proposed. Second, based on the convergence analysis of interpolation, objective function of parameter optimization is constructed by using the mapping between region sampling and point sampling. Finally, optimal parameters are obtained by iterative method which aims to reduce error for image interpolation. Experimental results show that this algorithm not only has lower time complexity, but also can preserve image details, eliminate phenomenon of edge aliasing, and have a high quality of interpolation image.