Objective: To understand whether the Newcastle disease virus(NDV) vaccine can successfully vaccinate the rabbits and volunteers of cancer patients by inhalation and to observe the effects of NDV vaccine on nasopharyngeal carcinoma (NRC) patients after radiotherapy. Methods: The live NDV vaccine was vaccinated through nasal cavities of rabbits, NPC patients and other cancer patients who were treated by surgery or chemotherapy with larynx spray. The blood specimens of vein from the tested rabbits and volunteers of patients with cancer were collected before and after vaccination. The anti-NDV-antibody in serum was detected by conventional blood coagulation inhibiting method. The white blood cell (WBC) amount in blood samples was counted. In addition, the NPC patients after radiotherapy were divided into both test group and control group with random match. The both were followed-up by multiple kinds of way in order to understand effects of NDV immunotherapy for NPC. Results: The anti-NDV-antibody level of the rabbits and the patients with NPC rose significantly after vaccination. The WBC amount of cancer patients treated by surgery or chemotherapy also rose significantly after vaccination. The recurrence rate (3.23%) of NRC patients in test group who received immunotherapy of NDV vaccine for 4 to 10 treatment courses within 3 years after end of radiotherapy were significantly lower than that (25.81%) of the control group (P