It is well-known that additional constraints emerge in light cone coordinates. We enumerate the number of physical modes in light cone coordinates and compare it with conventional coordinates. We show that the number of Schrödinger modes is divided by two in light cone coordinates. We study the effect of this reduction in the number of ladder operators acting on physical states of a system. We analyse the scaler, spinor and vector field theories carefully to see the effect of changes in the dynamical structure of these theories from the view point of the reduction of Schrödinger modes in light-cone coordinates. In this way, we propose an alternative expansion of dynamical variables which defer from other literatures.