We measured the angular dependence of critical currents on YBa2Cu3O7-y/PrxY1-r,Ba2Cu3O7-y superlattices at various applied magnetic fields and temperatures to investigate the effect of layer coupling on the dimensionality of the superlattices. The applied magnetic field was up to 6 Tesla and the temperatures varied from Tc to about 50 K. The angie between the applied magnetic field and the c-axis of superlattices were from 0° to 180°. The current was always perpendicular to the applied magnetic field. The Kes model was introduced to fit our data to study the dimensionality of the superlattices. For sample where the coupling is weak, the 2D Kes model has better fitting. These results will be discussed.