The transport properties of granular perovskite La0.83Sr0.17MnOz, were investigated. Tunnel-type giant magnetoresistance (GMR) and intrinsic crystal colossal magnetoresistance (CMR) have been observed simultaneously. With grain growth, the GMR effect gradually disappears whereas the intrinsic CMR effect is enhanced. These phenomena suggest that the tunnel-type GMR is strongly grain-size dependent and related to the properties of the interfaces between the grains.