More than 80% of rail corrugation occurs on the inner rail of small radius curved tracks,while almost no rail corrugation occurs on the outer rail of the same small radius curved tracks and on the rails of large radius curved tracks.In order to understand the mechanism of this phenomenon,based on the theory of rail corrugation caused by friction self-excited vibration,both Simpack multi-body dynamic model for vehicle curve negotiation and ABAQUS finite element model for rail corrugation were established.The complex eigenvalue analysis method was used to study the rail corrugation in small radius curved tracks.The results show that the occurrence probability of friction selfexcited vibration is decreased with the increase of curve track radius,and then probability of rail corrugation is decreased.Rail corrugation mainly occurs on the low rail,but less on the high rail.As the radius of curved tracks increases,the creep forces between wheels and rails will change from the saturation to nonsaturation states about in the range of radius from 400 to 450 m.When the creep force is saturated,the frictional self-excited vibration of the wheelsettrack system probably occurs,which brings about rail corrugation.Otherwise,no frictional self-excited vibration of the wheelsettrack system and rail corrugation occur.