Abstract: In order to analyze the rail stress and its mechanical characteristics under train loading more accurately,the rail is regarded as a three dimensional entity with the consideration of the influence of the supporting area of the fastener considered as the evenly distributed springs,thus establishing the mechanical model closer to the actual condition.Based on the analysis of the rail stress and displacement caused by the vertical force and the solution to the stress above sleeper,the comparison of the calculation results between the established model and the point-supported simplified beam model is made to point out the similarities and differences between them.Meanwhile,it is suggested that the modeling based on the three dimensional entity is more conducive to guiding the detailing of rail and sleeper.