Abstract: Objective To observe the changes of hemorheological index, blood gas analysis results and plasma D-dimer level in patients with chronic pulmonary heart disease at acute attack stage before and after treatment in order to evaluate their value as an index of the disease severity and curative effect. Methods Forty-six patients with chronic pulmonary heart disease at acute attack stage underwent general medical treatment for 2 weeks. Changes in hemorheological index and blood gas analysis results were detected and plasma D-dimer level was measured before and after treatment. Results Compared with 45 healthy controls, the hemorheological index, blood gas analysis results and plasma D-dimer（1.94±0.62mg/L）were significantly abnormal in patients with chronic pulmonary heart disease at acute attack stage. The hemorheological index, blood pH, PaCO₂ and plasma D-dimer level（0.79±0.46mg/L）were much more improved in patients with pulmonary heart disease after treatment than before treatment （P＜0.05 or P＜0.01）, but no significant change was observed in PaO₂. Compared with the controls, no significant difference was found in hemorheological index, blood pH, and plasma D-dimer level except for PaCO₂ and PaO₂ in the patients with chronic pulmonary heart disease （P＞0.05）. Conclusion The hemorheological index and blood gas analysis results are significantly abnormal in patients with chronic pulmonary heart disease at acute attack stage. Plasma D-dimer level can be used as an index to evaluate hypercoagulable state and pulmonary artery thrombosis and to judge the disease severity and curative effect in patients with chronic pulmonary heart disease.