Abstract: Application of beryllium alloy was joined with laser welding by taking aluminum as transition material.The mi-crostructure and properties of the welded joint were studied by means of scanning electron microscope (SEM) ,optical micro-scope (OM) ,and X ray diffraction apparatus (XRD) .The re-sults indicated that the microstructure was composed of quasi-composite compound phase formed by beryllium and aluminum.The shear strength lies between aluminum and beryllium.With percent of beryllium in weld zone being more,the size of berylli-um and beryllium particle distribution change,the shear strength of welded joint is higher,the fracture mechanism is transformed form ductile fracture with fractographs of dimples to brittle frac-ture with quasi-cleavage feature.The intermetallic compound in weld zone is the main cause of fracture for Be/Al/Be laser wel-ded joint.