Objective To study the biological activities ofthe nerve regeneration conditioned fluid (NRCF), especially to further separateand identify the protein bands of the relative molecular mass of (232-440)×103. Methods The silicone nerve regeneration chambers were implanted between the cut ends of the sciatic nerve in 6 New Zealand white rabbits (weight, 1.8-2.5 kg). The proteins in NRCF were separated by the native-polycrylamide gel electrophoresis (Native-PAGE), the protein bands of the relative molecular mass of (232-440)×103 were analyzed by the Shotgun technique, liquid chromatography, and mass spectrometry. Results The Native-PAGE result showed that there was 1 protein band of the relative molecular mass over 669×103, (232-440)×103 and (140-232)×103,respectively, and 6 bands of the relative molecular mass of (67-140)×103.Besides, 54 proteins were identified with at least 2 distinct peptides in 1 protein band of the relative molecular mass of (232-440)×103, including 4 unnamed protein products, mainly at the isoelectric points of 5.5-8.0 and of the relative molecular mass of (10-40)×103. Based on their functions in the protein database, allthe identified proteins in this study were classified into the following 5 groups: conjugated protein (43%), transport protein (30%), enzyme (6%), signal transducer (4%), and molecular function-unknown protein (17%). At the subcellular localization of the identified proteins, there was mainly a secreted protein (63%), and the remaining proteins were localized in the membrane and cytoplasm. Conclusion Native-PAGE and the Shotgun technique can effectively separate and identify proteins from NRCF, and can identify the components of the protein band of the relative molecular mass of (232-440)×103 and provide basicinformation on the unnamed protein products in NRCF.