Abstract: OBJECTIVE To establish human basophil activation test in vitro by flow cytometry, and to explore its feasibility of assessment of type I allergy reaction. METHODS By the theory of the specific expression of CD63 and CD203 in human basophil KU812 could be enhanced by positive agents, established in vitro model of type I allergy, which was verified by the result of human histamine enzyme-linked immunosorbent assay. RESULTS Human basophil activation test by flow cytometry was set up with positive agent of 2 μg·mL^-1fMLP for 2 h of incubation. The results of increase of cell histamine release percentage confirmed the positive establishment condition at the same time. CONCLUSION Human basophil activation test in vitro is a good cell model of anaphylaxis with the advantages of relatively simple and objective. It is a good animal alternative test for sensitization test with guinea pigs.