Let X be a manifold obtained by blowing up points of k-dimensioanl projective space. We say f: X ----> X is a pseudo-automorphism if for every codimension 1 variety H, both the codimensions of f(H) and f^{-1}(H) are equal to 1. In this talk , we will discuss an explicit method for constructing pseudo-automorphisms on X. The centers of blowups are chosen to lie on an algebraic curve of degree (k+1) with one singular point and are determined using the arthmetic on the curve. These pseudo-automoprhisms have dynyamical degree greater than 1. This is a joint work with Eric Bedford and Jeffery Diller.