A coating agent for oil seal comprising 10 to 160 parts by weight of a filler having a particle size of 0.5 to 30 □m based on 100 parts by weight of isocyanate group-containing 1,2-polybutadiene and being prepared as an organic solvent solution, wherein a contact angle between a substrate surface coated with the coating agent and engine oil is less than 35°. The coating agent can improve wettability with oil and reduce dynamic friction coefficient in oil, while increasing the roughness of the coating surface. Thus, low torque characteristics can be achieved, while maintaining excellent seal performance inherent in oil seal.