Abstract: Objective: To investigate the clinical value of the heart rate variability(HRV) in the assessment of the prognosis of patients with chronic pulmonary heart disease.Methods: The HRV in 80 patients with chronic pulmonary heart disease(pulmonary heart disease group) and 80 healthy physical examinees(control group) were analyzed.Results: Compared with the control group,the standard deviation of normal to normal R-R intervals,standard deviation of sequential five-minute R-R interval means and percentage of NN50 in the total number of N-N intervals significantly decreased in pulmonary heart disease group,and the differences of whose between two groups were statistically significant(P<0.01).The differences of the standard deviation of normal to normal R-R intervals,standard deviation of sequential five-minute R-R interval means and percentage of NN50 in the total number of N-N intervals in patients with different impairment of pulmonary function in pulmonary heart disease group were statistically significant(P<0.01).Conclusions: The heart rate variability has important clinical value in evaluating the severity and prognosis in patients with chronic pulmonary heart disease.