Abstract: ObjectiveTo analyze the clinical and special laboratory features of one case with BCR/ABL P230 positive chronic myeloid leukemia (CML) patient through reviewing comprehensive literature and to identify the disease with chronic neutrophilic leukemia (CNL) and improve the level of diagnosis and treatment. MethodsLaboratory tests included routine blood examination， bone marrow，histochemical staining， chromosome examination， detection of fusion gene and analysis comprehensively. ResultsRoutine blood test did not show anemia， but increased white blood cells， platelets， many times white blood cell classification: neutrophil all >0.86. The bone marrow showed very active and active proliferation of nuclear cells， and the proliferation of the cells in the middle and late stage， and eosinophils and basophils easily seen. Tissue chemical staining of alkali phosphatase was negative. Ph chromosome positive， t(9; 22) (q34; q11)，BCR breakpoint was in the μ BCR，with the corresponding BCR of e19a2，coding protein was P230. ConclusionThe Ph+BCR gene rearrangement should be diagnosed CML， and not  diagnosed as CNL， no Ph chromosome and BCR/ABL fusion gene is the real CNL.

Key words: leukemia；myelogenous；chronic；BCRABL positive；fusion , proteins；bone marrow examination