Abstract: In this paper, univariate splines are extended to bivariate Box splines, and some properties of Box splines are given, which are valuable in image processing. Then a method of computing filter bank is presented by using a particular class of bivariate Box splines. This filter bank is a perfectly reconstructing one in the four band analysis/synthesis scheme. It can be used to decompose and reconstruct images efficiently. Finally, an example is given to demonstrate this method.