This paper describes channeling of liquid flow in copper ore heaps used for chemical or bio- leaching. The size of packed beds utilized as heap is 5 by 5 meters and the height is 3.5 or 5 meters. Tracer tests with lithium as tracer were carried out to investigate the liquid flow within the heaps. The experimental results were analyzed by the advection diffusion model with multiple step-wise liquid flow pattern. As a result, the maximum liquid velocity was 3.8 times larger than the average velocity at the final stage of leaching while the maximum was 1.4 times larger than the average at the initial stage of leaching. These results indicate that the channeling is clear quantitatively and become larger with time.