A nonlinear two-degree-of-freedom system is used to construct an aircraft landing gear model. The stochastic excitation of the uneven runway to the system is described by time-domain noise， and the road roughness coefficient is used to describe the roughness of runway. Based on the probability density function and the statistics of system response， the influence of uneven run? way on aircraft landing gear system is investigated. The reliability of the landing gear model and the passenger comfort under differ? ent road roughness coefficients are analyzed by establishing the relationship between the safety zones， comfort zones and the sys? tem response. The results show that the larger the road roughness coefficient is， the more fluctuation of the system state variable will be. The reliability and comfort of the system are negatively correlated with the road roughness coefficient. In addition， when the road roughness coefficient is small， the mean first-passage time and comfort of the system are more significantly affected by ran? dom disturbance. The present paper provides a theoretical basis for aircraft riding comfort and landing gear development and design.