The angular dependence of the resistivity ϱ(θ) has been measured in the superconducting transition region at various magnetic fields on films of the Y 1- xPr xBa 2Cu 3O y system. The angular dependence of ϱ(θ) was analyzed on the basis of the effective mass model. The obtained anisotropy ratio ∊=ξ ab/ξ c between the c-axis and the c-plane is almost constant in the samples with x below 0.08 and then increases with the Pr concentration x from 5.5 for x=0.08 to 10.1 for x=0.45. Superconducting properties are not affected by the small substitution of Pr ions below x=0.08 and the two-dimensional character is enhanced with increasing x above x=0.1. It is pointed out that the increase of the anisotropy is due to a weakening interlayer coupling between the superconducting CuO 2 planes and is caused by the suppression of superconductivity in the CuO chains which is similar to that in the oxygen-reduced YBa 2Cu 3O y system.