Objective To study the relationship of immunophenotype and FAB phenotype and guide clinical analysis and treatment.Methods Cell morphology checking and immunophenotyping were performed at the same time for the 505 patients with leukemia,flow cytometry had used for immunophenotype,on the end the results had been analyzed to understand the relationship between the two phenotypes.Results ①Among the 505 cases of leukemia,there were AML(248)、ALL(200)、CML(18)、CLL(15)、HAL(14)、UAL(10) in FAB phenotype and AML(163)、Ly+AML(83)、ALL(108)、My+ALL(106)、HAL(32)、UAL(13) in immunophenotype.② In AML the accordance rate and part accordance rate of the two phenotypes was 61.3% and 30.2%.In ALL the accordance rate was and part accordance rate was 53% and 44.5%.In HAL the accordance rate was 42.9%.Conclusion Immunophenotype plays an important role to distinguish AML、ALL subtype、variants leukemia and HAL.Immunophenotyping was shaper and more accurate than FAB phenotype,and is a supplementary and correction,but it can not replace the FAB phenotype.Combination of both can improve the diagnostic accuracy.