To analyze the clinical features,therapeutics effects and prognosis of patients with bone marrow involvement(BMI) in malignant neoplasm.The diagnosis of BMI was performed by bone marrow aspiration and biopsy.One hundred and four patients were divided into two groups: 26 patients with hematologic abnormalities (group 1) and 78 patients without hematologic abnormalities(group 2).The clinical characteristics,response to treatment and survival were investigated retrospectively.Hematologic abnormalities included Anemia and thrombocytopenia,pancytopenia and disseminated intravascular coagulation (DIC).Except 6 patients of acute DIC died soon after initial diagnosis,all patients received chemotherapy and supportive treatment.In group 1,18 patients died.In group 2,42 patients died.The median survival time was 7 months and 24 months respectively.The result showed that B symptom,ECOG,LDH,OS and PFS rates between two groups had significant difference (p<0.01-0.024).These data suggested that early diagnosis and treatment may improve clinical outcome of BMI,particularly the patients were absent in hematologic abnormalities.The key to early diagnosis is bone marrow aspiration and biopsy in time.The patients with hematologic abnormalities of BMI in malignant neoplasm had worse prognosis than the patients without hematologic abnormalities.