Objective To study the effect of anterograde-tracing the corticospinal tract of the rat using DiI a tracer. Methods Twenty-four Wistar rats were randomly divided into DiI group and degeneration group. 5% DiI were stained on the motorsensor cortex of the DiI group rats; the corresponding cortex of the degeneration group were destroyed.After 5d,10d,15d and 20d,the rats were killed respectively.The brains and spinal cords were sliced and observed. Results In the 5d DiI group,labelled fibers were only observed both in telencephalon and diencephalon,and in 10d,15d and 20d groups,corticospinal tracts were well labelled through the brain and spinal cord.In the degeneration group,black degenerating fibers of the spinal cords were well demonstrated,especially in the 5d group.However, above the spinal cords,no obvious degenerating fibers could be found.Conclusion It’s a simple,convenient and valuable method,using DiI as an anterograde tracer,to trace corticospinal tract,especially the part through midbrain to spinal cord.