Objective To investigate the biocompatibility of coaxial electrospun poly(L-lactic acid-caprolactone)/bovine serum albumin [P(LLA-CL)/BSA] nanofiber membranes in vivo and in vitro.Methods The P(LLA-CL)/BSA nanofiber membranes were fabricated by coaxial electrospinning. The Schwann cells (SCs) of SD neonate rats were seeded on the nanofiber membranes(as material group) and blank TCPs(as control group) after isolation and culture in vitro. At different times, the cyto-activity, growth, adhesion and proliferation of SCs on the nanofiber membranes were measured respectively by MTT, phase contrast microscopy and scanning electron microscopy (SEM). The nanofiberous materials were implanted into the paraspinal muscle in rats to evaluate by light microscopy at different times the foreign-body reaction and the encystment surrounding the biomaterials. Results Compared with the control group, MTT showed better proliferation activity of SCs on the surface of nano-fibrous mats at 3 d, 5 d and 7 d ( P<0.05). SEM showed that SCs adhered and proliferated well on the surface of the nano-fibrous mats. SCs demonstrated long olivary and long fusiform shape with obvious prominence, connected end-to-end with each other or aligned in clusters. The sections of HE staining showed that the tissue reaction of P(LLA-CL)/BSA at the biomaterial interface was mainly dominated by the presence of lymphocytes early after implantation. The inflammatory reaction obviously decreased with implantation time, and the thickness of fibrous capsule grew thinner gradually. At 12 weeks, lymphocytes were no longer present at the polymer interface, only giant cells were sporadically detected, and the fibrous capsules almost disappeared. Conclusion The P(LLA-CL)/BSA nanofiberous material has good biocompatibility in vivo and in vitro.