A regenerated brass RE-Bi was developed to improve the difficulty of reusing the waste of traditional bismuth brass due to its cold and hot brittleness.The microstructure of the alloys were observed by optical microscope and scanning electron microscope,and the mechanical properties were measured by tensile test.The results reveal that RE can refine grain size of the as-cast alloy,and Bi is uniformly distributed into the matrix from film to granular.As the addition of RE increases,the elongation of both as-cast and hot-rolled alloys is increased firstly and then decreased,and the desirable mechanical properties can be observed with 0.2% RE addition.When the addition of RE is more than 0.2%,excessive RE compounds are generated in the alloy,which weakens the mechanical properties of the alloy.