Abstract: The weldability of SiCp/6061AlMMCs was studied with plasma arc welding.The effect of welding parameters(welding current, welding speed)on the microstructure and mechanical properties of welded joint with and without filler Ti was investigated.The results showed:Without the filler Ti, the welding parameters can only change the dimension and quantities of Al₄C₃ which is the harmful particles, but not restrain its generation;with the filler Ti, types and distribution of reinforcement phase are the main factors to affect the mechaical properties of welded joint.Adjusting the welding parameters properly is beneficial to form a completely new in-situ section with the TiC TiN and AlN as the reinforced particles can beformed at the weld center.Meanwhile the width of the old and new reinforced phases coexistence is reduced and the segregation of reinforced SiC particles is eliminated, thereby the mechanical properties of welded joints is enhanced.