ANISOTROPIC TRANSPORT-PROPERTIES OF PRBA2CU3O7

The in-plane resitivity is measured on the twin-free PrBa2Cu3O7 crysta ls. The observal anisotropy indicates that dominant carrier conduction takes place in the CuO one-dimensional chain. By applying the pressur e, rho(a), containing CuO2 plane contribution increases more rapidly t han rho(b), containing both chain and plane contributions. This is con sidered to be due to the increased the hybridization between Pr4f and O2p orbital at the plane site, consistent with the scenario proposed b y Fehrenbacher and Rice.