The scattering property of TMz illuminated perfectly conducting and dielectric cylinders of arbitrary cross section are analyzed by the boundary element techniques. The boundary element equations are formulated via Maxwell’s equations, weighted residual or Green’s theorem, and the boundary conditions. The unknown surface fields on the boundaries are then calculated by the boundary element integral equations. Once the surface fields are found, the scattered fields in from a perfectly conducting circular and elliptic cylinders, a dielectric circular and elliptic cylinders are numerically analyzed. A general computer program has been developed using the quadratic elements(higher order boundary elements) and the Gaussian quadrature.