Effects of the mold rotating speeds on the gradient microstructure and properties of heavy cross-sectional WCp/Fe-C composites made in a self-made centrifugal machine have been investigated with SEM, EDS etc. The results show the ring sample of WCp/Fe-C composites made in a centrifugal machine was free of any defects. And the transition layer between the working layer of WCp/Fe-C composites and matrix Fe-C alloy core was also perfect. The experimental results also show that the WCp-radius-directional distribution in the composites was a continuous component gradient one, which was changed with the various mold rotating speeds. At 1000 rpm the volume fractions of the WC particle from outer layer to inner layer were about 70 vol% to 50 vol% and, at 1400 rpm the volume fractions were about 80 vol% to 65 vol% respectively. The hardness and impact toughness of the working layer of WCp/Fe-C composites were changed with increasing of the mold rotating speeds respectively. Finally, the mechanism of the effects of the mold rotating speeds was discussed in the paper.