To eliminate or reduce maintenance burden in any seasons, to allow horses to exercise racing to run the racecourse in a good run and safely, and to obtain a good cushioning in particular, by making the racecourse with a surface stratifying substratum for racecourse that is coated with an oil-absorbed/ swollen oil-absorbent resin.

An oil-absorbent resin with a tertiary-bridging structure as an oil-absorbent resin acquiring a surface stratifying material for racecourse a water-soluble oil as an oil to be absorbed into the oil-absorbent resin and sand/wooden chips, etc., as a surface stratifying substratum for racecourse, are employed. Putting-into/mixing with a mixer the surface stratifying substratum for racecourse and appropriate amounts of oil-absorbent resin/oils at a room temperature, result in having the oil-absorbent resin absorb the oils to become a swollen state, which is then coated throughout the peripheral surface or locally over the surface stratifying substratum for racecourse. This surface stratifying substratum contains the oils to demonstrate both the viscosity and repellence, thus, obtaining the surface stratifying material demonstrating a rich cushion via the cushioning ability by the surface stratifying substratum and the elasticity by oil-swelling the oil-absorbent resin.