Four kinds of ZrC coatings with nearly the same thickness have been successfully prepared on graphite substrate by chemical vapor deposition (CVD) through controlling the ratio of inlet reacting gases.From backscattered electron images, it can be inferred that ZrCⅢ coating has the best tightness of all coatings.Meanwhile, line energy spectrum curve shows zirconium and carbon elements distribute uniformly along the normal direction of the ZrCⅢ coating.As for varied microstructures, the coatings show different mechanical properties and residue stress.The hardness and Youngs modulus of ZrC Ⅲ coating were up to 89570Mpa and 1192.5Gpa, respectively.Those make it near the level of of diamond.Value of residue tensile stress of ZrC+C composite coating was only 7.729Mpa and that of ZrCⅢ coatings was 349.632Mpa.The strong combination of small-size grains in ZrCⅢ coating play a decisive role to best mechanical properties.But strong misfit of lattice between ZrCⅢ coating and substrate can induce high residue stress.