Abstract: 【Abstract】Objective：To observe the effect of Phentolamine combined with low molecular weight heparin on hypercoagulability in patients with cor pulmonale in acute exacerbation stage. Methods： 104 patients with cor pulmonale in acute exacerbation stage were randomly divided into treatment group and control group. Two groups of patients were given conventional treatment of pulmonary heart disease such as oxygen therapy, strong heart, to improve ventilation, control of infection; 52 cases in treatment group treated with phentolamine and low molecular weight heparin on the basis of conventional therapy;trong heart, to improve ventilation, control of infection; 52 cases in treatment group treated with phentolamine and low molecular weight heparin on the basis of conventional therapy; 52 cases in control group were given conventional treatment on the basis of conventional therapy. Hypercoagulability was examined and compared between the two groups. Results：The treatment group?(52 cases)?and control group?(52 cases)?of patients before treatment?of whole blood high shear?viscosity,?whole blood shearviscosity,??plasmaviscosity,?hematocrit,?platelet?aggregation?and fibrinogen showed no?significant difference,?P > 0.05;?after treatment,?the treatment group?of whole blood high shear?viscosity,?whole blood low shear?viscosity, plasma viscosity,?hematocrit,?platelet?aggregation and fibrinogen?was obviously lower than that in control?group,?compared with statistical?difference, P < 0.01or0.05.Conclusion：Phentolamine combined with low molecular weight heparin in treatment of patients with cor pulmonale in acute exacerbation stage can significantly improve the hypercoagulability, which had less adverse reaction but had satisfactory effect.