Thrombocytopenia in children may be caused by insufficient platelet production, excessive platelet destruction, and abnormal platelet distribution. 1. Insufficient platelet production: aplastic anemia, acute leukemia or infections can cause insufficient platelet production and reduced number. 2. Excessive destruction of platelets: certain drugs such as sulfonamide and chloramphenicol can produce anti-platelet antibodies through immune mechanism, resulting in thrombocytopenia. There are also some primary thrombocytopenia, thrombotic thrombocytopenia, systemic lupus erythematosus and so on will also cause thrombocytopenia. 3. Abnormal distribution of platelets: If there is hypersplenism or splenomegaly, platelets will be retained in the spleen, and the examination at this time will also find that the number of platelets in the blood is reduced. Thrombocytopenia in children is prone to subcutaneous and mucous membrane bleeding, the cause of the disease should be clarified and the treatment should be targeted. All of the above medications should be used under doctor’s supervision, avoid self-medication.