Abstract： Objective To explore the clinical significance of the coagulation and fibrolysis parameters changes for the knowledge of complicated thrombosis after chemotherapy in malignant lymphomas. Methods Morning fasting anti-coagulation blood samples were taken to detect plasma prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB) and thrombin time (TT) with automatic coagulation analyzer in 71 hospitalized malignant lymphomas and 20 normal controls. The plasma D-dimer levels of the two groups were detected with immunoturbidimetry. Results The levels of plasma APTT, Fib and D-dimer in 71 malignant lynphomas were (30.44±1.43) s, (3.28±0.20) g/L, (297.05±56.59) μg/L respectively, which were significantly higher than those in normal controls at the levels of (23.72±0.76) s, (2.57±0.22) g/L, (94.50±26.07) μg/L respectively (P ＜0.05). The coagulation and fibrolysis parameters were of no statistic differences between the normal controls and lymphomas of stage Ⅰ and Ⅱ (P ＞0.05). The APTT and Fib levels in lymphomas of stage Ⅲ and Ⅳ were higher than those in normal controls and lymphomas of stage Ⅰ and Ⅱ (P ＜0.05). There are 7 malignant lymphomas complicated venous thrombosis . Of the 7 cases, the FIB and D-dimer levels were higher than those of stage Ⅰ and Ⅱ, furthermore the D-dimer levels were higher than those of stage Ⅲ and Ⅳ. Conclusion The abnormalities of coagulation and fibrolysis parameters occurred in malignant lymphomas with requirement of periodic monitoring. After chemotherapy, the lymphoma patients had a high incidence of venous thrombosis, which need early prevention for prolongation of the survival.