Abstract: A two-dimensional finite element model of linear friction welding (LFW) of similar joints was established based on the ABAQUS/Explicit software. The characteristics of LFW joints of steel 45 with Chinese Standard (steel 5C), including temperature, stress, strain fields, axial shortening and the cooling process, were investigated. The results show that the interfacial temperature can increase to 800℃ rapidly within 1s under a certain processing condition, and then increases to about 900℃ slowly. With the progressing of welding, the temperature change of the welding joint gets uniform and becomes short to continuously contract in axial direction, the flash of the joint forms, and then the joint undergoes a rapid cooling process. The experimental results verify the reliability of the present model.