The project of flow cytometry (FCM) detection is constantly pushed from scientific research to clinical application, and plays an indispensable role in clinical immunology, diagnosis, treatment and recurrence monitoring of hematological diseases. The role of FCM in clinical examination and diagnosis is becoming more and more important, and there are more and more medical institutions carrying out FCM in China. However, there are still many problems, and the overall level needs to be further improved. At present, there is still a lack of unified guidelines for the application of FCM in clinical practice. In order to scientifically and reasonably apply FCM to clinical disease screening, diagnosis, efficacy monitoring, prognosis evaluation, recurrence prediction and other links, the Laboratory Medicine Branch of Chinese Medical Association, the Clinical Laboratory Center of the Ministry of Health and the Editorial Committee of Chinese Journal of Laboratory Medicine jointly decided to formulate the clinical application recommendations of FCM. In the process of formulating this application recommendation, we mainly referred to the American Clinical and Laboratory Standards Institute (CLSI) and the European Working Group on Clinical Cell Analysis (EWGCCA)[1,2,3]Academic organization of relevant documents on the clinical application of flow cytology, and extensive consultation of clinical hematology experts and laboratory medicine workers through various ways, as an important reference basis for the revision of this recommendation.