A novel type of steel buckling-restrained braces (BRBs) is proposed, in which the core plate is perforated, termed as PBRB. PBRB is composed of a perforated core plate, 2 filling plates and restraining plates, which are assembled by bolts. Quasi-static cyclic tests and the corresponding numerical analyses were carried out on 3 specimens with different configurations of holes, the effect of which on the seismic performance was investigated emphatically. It was showed that PBRBs had stable hysteretic properties, high ductility and energy dissipation capacity. The compressive deformation of perforated core plates was found to be composed of compression, shear and flexural deformation. The slenderness ratio of "stub columns" is a critical parameter that affects seismic performance of PBRBs. An oversized slenderness ratio can lead to relatively poor seismic performance. A conservative design limit for the slenderness ratio was proposed based on the experimental results. A method with good accuracy has been proposed to evaluate initial stiffness of PBRBs.