Abstract: Objective To investigate the clinical and therapeutic effects of hairy cell leukemia(HCL). Methods The clinical and laboratory characteristics of twenty-one patients with HCL were retrospectively analysed. Results Splenomegaly was the most common physical phenomenon.The others were pancytopenia and active bone marrow hyperplasia.Ribosomal-lamellae only accounted for a few patients.Classic HCL cell expressed CD11c,CD25,CD123,CD103, and companied with CD20,CD22,CD52 and Cyclin D1 expression.Especially,CD103 was HCL specific immunophenotype.The purine nucleoside analogues presented better therapeutic effects than other regiments. Conclusion The HCL clinical characteristics are similar to that in western patients.In Chinese patients fludarabine-based combination regimens has no significant accumulation of bone marrow inhibition,and the therapeutic effect is higher than that in foreign patients.