Electrospun nanofibrous materials are considered as ideal scaffolds for tissue engineering because their fibrous structure is quite similar to the morphology of natural extracellular matrix, and they can offer biomimetic microenvironment for cell growth. However, the highly porous scaffolds are too weak to meet the mechanical requirement of guided tissue regeneration (GTR). In the present investigation, electrospun L-polylactic acid (PLLA) nanofibrous membranes were collected with high speed rolling method, and then hot stretched and annealed to improve the tensile strength and cell occlusivity. The membrane with the maximum tensile strength (strength 103MPa and modulus 1.83GPa) was obtained by hot-stretching for twice at 100 degrees C and further annealed for 10min at the same temperature. Cytotoxicity test showed that the heat treated membrane supported well the attachment and growth of human periodontal ligament cells, but inhibited the cell proliferation. The cell occlusivity of the membrane was also significantly improved as the porosity decreased after heat treatment. It could be used as the enhancement interlayer of barrier materials for GTR.