A numerical model is presented to analyze effect of wheel/rail friction on rolling contact fatigue. A three-dimension finite element model of rail is built up to investigate the rail stresses and strain around wheel/rail patch. Then, based on the critical plane concept, a new model was proposed to predict the rolling contact fatigue (RCF) crack initiation life under different wheel/rail frictions by using stress and strain on the critical plane as fatigue parameter. The numerical results obtained show that the wheel/rail friction coefficient has a great impact on the fatigue crack initiation life.and the curve of fatigue crack initiation life under different wheel/rail friction coefficient is roughly "S" type. The results are very useful in the wheel/rail friction management and determining grinding interval and grinding removal.