The periosteum plays a very important role in bone remodeling and regeneration due to its excellent osteogenic ability. However, in bone defects, the periosteum is inevitably damaged, has poor self-repair ability, and requires artificial materials as a substitute. This study is aimed to fabricate a highly bioactive poly(epsilon-caprolactone)/tricalcium phosphate sol (PCL/TCP sol) hybrid membrane as an artificial periosteum covering the surface of the bone defect to enhance bone regeneration. Three kinds of PCL membranes with different TCP contents were prepared and marked as P20T1 (4.8 wt %), P10T1 (9.1 wt %), and PST1 (16.7 wt %). The physicochemical properties' evaluation confirmed that TCP sol was homogeneously dispersed in the PCL nanofibers. Compared with P5T1, samples P10T1 and P20T1 had enhanced the mechanical properties and a moderately hydrophilic surface (67.3 +/- 2.4 degrees for P20T1 and 48.9 +/- 4.1 degrees for P10T1). The biomineralization of hybrid membranes was significantly improved compared to the PCL membrane. Moreover, hybrid membranes significantly upregulated the rat bone marrow mesenchymal stem cells' (rBMSCs) response (proliferation and osteogenic differentiation) to them, and P10T1 showed better surface properties (hydrophilicity, bioactivity, and biomineralization) than P20T1. Thus, sample P10T1 with the best properties in this study has great potential as an artificial periosteum to accelerate bone regeneration.