Abstract: Objective To separate and purify exosome derived from transitional cell carcinoma of bladder of T24 cell,and initially analyze the morphology and protein composition in order to offer a foundation for its utilization in immunotherapy. Methods The exosomes secreted by T24 cell were purified by ultracentrifugation and sucrose gradient centrifugation,and the electron microscope was used to check the exosome.Proteins were separated by SDS-PAGE,and protein bands were analyzed by software. HSP70,ICAM-1 and CK20 were identified by western blot. Results Exosomes were successfully purified by ultracentrifugation and sucrose gradient centrifugation. The exosomes were syngeneous in size about 30~90nm, and were saucer-shaped membrane vesicles. HSP70,ICAM-1 and CK20 were detected by western blot. Conclusion It was confirmed that T24 cell can secrete exosome,and the presence of immune proteins of HSP70 and ICAM-1 offer a theoretical foundation for anti-tumor in immunotherapy.