Reliability evaluation was performed on the cylinder liner of a low-speed marine engine experiencing high-cycle fatigue with high mean stress. The stress distribution in the cylinder liner under operating condition was estimated through structural analysis, which included thermal boundary conditions and material nonlinearity. Results indicated that the highest stress concentration developed at the round part below the liner collar. Material tests revealed that the Goodman relation can predict the effect of mean stress on fatigue limit. As indicated by the combined results of the structural analysis and experiment, the cylinder liner is reliable under operating condition.