Abstract: In the previous fabrication process of surface composite by friction stir process(FSP),the reinforcement phases were needed to preplace on the base metal.However,these particles didn't distribute very well in the stir zone.Therefore, friction stir process without preplacing reinforcement phase was proposed to prepare the surface composite.A FSP tool consisting of only shoulder was designed,and used to fabricate the surface composite on the AZ31 plate as-rolled.Microstructure was analyzed by optical microscope and SEM.The microhardness and surface wear resistance tests of specimens show that the particle reinforcement are more homogeneous,so that the microhardness and wear resistance increase,and at the same time,the preparation work is simplified to a great extent.