The gusset plates in a braced frame structure can be subjected to the forces from the effects of brace and frame actions. In this study, several finite element models are constructed to analyze the gusset to beam and column interface forces. It is found that the frame actions affect the gusset interface force distributions significantly. A simplified strut model to represent the gusset plate is adopted to evaluate the frame action forces. In addition, the Generalized Uniform Force Method (GUFM) is adopted as it provides more freedom for designers to configure the gusset plate shapes. In this paper, a performance-based design method is proposed. The gusset interface force demands take into account the effects of the brace maximum axial force capacity and the peak beam shear possibly developed in the frame. The specimen design and pseudo dynamic test results of a full-scale 3-story buckling-restrained braced frame (BRBF) are discussed. The BRBF gusset interface cracks observed at the inter-story drift greater than 0.03 radians can be predicted by using the proposed design method. This paper concludes with the recommendations for the seismic design of gusset plates.