•Poly(l-lactic acid/caprolactone) (PLCL) bilayer membrane was developed for GBR application.•Controlled degradation of PLCL bilayer membrane was achieved.•The PLCL bilayer membrane showed suitable mechanical properties.•The PLCL bilayer membrane exhibited high biocompatibility.•The porous layer of PLCL membrane promoted osteoblastic differentiation. Guided bone regeneration (GBR) often involves the use of membranes as barriers for soft tissues. Commercially available membranes, however, do not possess an adequately low degradation rate, resulting in limited barrier function. The purpose of this study was to develop and assess the physicochemical and biological characteristics of a novel poly(l-lactic acid/caprolactone) (PLCL) bilayer membrane and determine its usefulness for GBR application. The experimental bilayer membrane was prepared via a two-step freezing and lyophilization process with a PLCL solution. Next, the PLCL membrane was investigated regarding tensile strength, surface roughness, in vitro degradation and clinical operability. In addition, cell proliferation and differentiation were investigated on each layer of the experimental membrane. For all experiments, a commercially available poly(lactic-co-glycolic) acid membrane was used as a control. In vitro analysis of the PLCL bilayer membrane revealed suitable mechanical strength combined with high breaking strain, which contributed to membrane operability. In addition, the PLCL bilayer membrane had enhanced stability compared to the commercial control due to its slower degradation, and was capable of supporting cell growth and osteogenic differentiation. The current study confirmed that the PLCL membrane possessed a high biocompatibility and slow degradation rate that contributes to prolonged barrier function and bone regeneration. Altogether, it was considered that the PLCL bilayer membrane developed in this study was applicable for GBR treatment.