Abstract: Mechanical properties of friction stir welded 7N01 aluminum joint under different welding parameters have been studied in this paper.The tensile test results showed that,with a certain rotational speed and welding speed,the FSW joints could keep at a high strength level of 340 MPa even the plunge depth varied from 0.3 to 1.0 mm.SEM was carried and the FSW joints exhibited mainly dimpled fracture surfaces.Hardness of the joints was also measured.The hardness in retreating side was a little higher than that of advancing side.This result corresponded well with the tensile test result.Fracture occurred at the advancing side in tensile test.