The work aims to study the influencing law of surface graphite content on cylinder scoring resistance of cast iron cylinder liner. Based on lean oil test, the cylinder scoring test was performed to the cast iron cylinder liners at different contents of surface graphite including 0.18%, 1.27%, 2.13%, 3.92%, 4.66% and 5.88% respectively. The cylinder scoring time was recorded during the test. Surface morphology was observed and composition of cylinder liner was analyzed by virtue of scanning electron microscopy (SEM). Exposure of graphite on the surface of the cast iron cylinder liner could prolong the time of cylinder scoring. However, as the content of surface graphite increased, the cylinder scoring time first increased tendency and then decreased. When the content of surface graphite was 4.66%, the time of cylinder scoring was 8 h, 9.6 times of that without graphite coating. The graphite exposed on the surface of the cylinder liner plays an important role in oil storage and solid lubrication, improving the adhesion resistance of matched pair. On the other hand, as graphite in soft phase, overall carrying capability of the cylinder sleeve decreased and may be subject to cylinder scoring easily when the content of surface graphite increased.