Abstract: The brazed butt joint of brass plate was obtained with CuPSn brazing filler metal,and the tensile strength was measured.The microstructures and fracture morphology of the brazed joint were analyzed by scanning electron microscopy and energy dispersive spectrometer.The results show that the CuPSn brazing alloy and base metal achieve a good metallurgical bonding and the brazing zone is mainly composed of bright white phases and grayish black phases.In addition,the grayish black phase in the joint was in the form of a little black sheet cell crystal,and the bright white phase was consisted of solid solution and（α+δ）eutectoid with the dendritic interphase distribution.The fracture source in the brazed joint is the brazed interface and the fracture comprised of a large number of high-density short and curved tear edges and quasi-cleavage zones which are shallow and large.