Abstract-Reflection from a perfect electric conductor (PEC) plane of infinite dimensions embedded in a second order nonlinear medium is studied. The reflected wave has two parts, one due to linear behavior, the other due to nonlinear behavior of the medium. The expressions of the reflection coefficients for parallel and perpendicular polarization cases are obtained. The reduction of reflection coefficient to a linear medium case is also reported. Dependence of the said coefficients on incident electric field intensity and the angle of incidence is also plotted.