Abstract: Several new types of core-separated buckling-restrained braces (CSBRBs) were proposed in this paper. Compared with traditional buckling-restrained braces, CSBRBs have the potential to be widely used because of their lightness and convenience in fabrication and erection. The chord members of CSBRBs contain two traditional single-core BRBs connected by continuous web plate longitudinally. The separating section is very helpful to improve the bending stiffness, thus the brace material of CSBRBs is utilized more efficiently. Therefore CSBRBs can be used as a kind of large-tonnage buckling-restrained brace in building structures. As an important parameter for calculating restraining ratio, the elastic buckling load of pin-ended CSBRB was first obtained by energy method, and then verified by finite element elastic buckling analysis. This research provides basis for further investigations on CSBRBs.