Abstract: Objective To analyze the changes of five blood coagulation indexes and exploretheir clinical significance inpatients with acute promyelocytic leukemia （APL）. Methods Prothrombin time （PT），activated partial thromboplatin time （APTT），fibrinogen，thrombin time （TT） and D-dimer were tested by CA-7000 coagulation analyzer in 203 acute leukemia cases including 46 APL （18 with high-risk and 28 with low/intermedia-riskfollowed byDIC complications），157 non-APL cases and 30 normal controls. Results Compared with the control，PT and D-dimer level were elevated in APL and non-APL groups （P＜0.05）.Fibrinogen was found to be decreased in APL group than in the control and non-APL group （P＜0.05）.No significant difference of APTT and TT was noted in the three groups （P＞0.05）. PT level was high in the high-risk group than in the low/intermedia-risk group （P＜0.05） although APTT，TT，FIB and D-dimer did not show any significant difference inthe two groups （P＞0.05）. APL with subsequent DIC complications exhibited a high level of PT and D-dimer and lower level of FIB （all P＜0.05）. Moreover，PT was negatively correlated with FIB （r=–0.43，P＜0.05） and positively with WBC （r=0.46，P＜0.05）. Conclusion The elevated PT is related to the severity of APL patients，an abnormally high level of PT and/or D-dimer and low level of fibrinogen might be valuable for early diagnosing APL with DIC.

Key words: Promyelocyte , Leukemia , Prothrombin time, D-dimer, Fibrinogen