Objective Investigation on nutritional K⁃A⁃P of medical staff in the oncology in order to enhance the attention of medical staff to nutrition therapy and provide a basis for the effective education of nutrition. Methods From June 2018 to December 2018, 30 provinces (autonomous regions and municipalities directly under the central government)，1972 hospitals and 6898 medical personnel were investigated by multi⁃center and observational study, and the results were analyzed statistically and compared with the survey results of cancer nutrition knowledge, attitude and behavior of medical staff in China in 2013. Results The scores of nutrition knowledge (K), pass rate (41.51%), excellent rate (20.65%), nutrition attitude (A), pass rate (97.94%), excellent rate (81.92%), nutrition behavior (P), (75.04±16.34) score, pass rate (85.41%), excellence rate 46.49%. There were significant differences in nutritional K score (P<0.01) and nutritional A score (P=0.034) between different sexes. There were significant differences in nutrition K score (P<0.01), nutrition A score (P<0.01) and nutrition P score (P<0.01).There were significant differences in nutrition A score (P<0.01) and nutrition P score (P<0.01) among different specialties. The top 3 ways to acquire nutrition knowledge are working practice learning, reading related books and periodicals, and studying in school before graduation. The scores of K,A and P of medical staff in 2018 were significantly higher than those in 2013（all P<0.01）. Conclusion The level of nutrition knowledge⁃attitude⁃behavior of medical staff in China has been improved obviously, and the status of general nutrition knowledge⁃attitude⁃behavior has been improved obviously, especially in the process of tumor nutritional therapy, there are still positive attitude and good nutritional therapy behavior, but the degree of mastering nutritional knowledge needs to be further improved, which is still the focus of nutrition education in the future.