Objective To observe the pulmonary artery motion curve with anatomical M-mode echocardiography, and to investigate its influential factors. Methods The pulmonary artery motion curve was detected and pulsating amplitude of pulmonary artery wall (PAWPA) was measured with anatomical M-mode echocardiography in 160 patients with normal pulmonary artery pressure. Intraclass correlation coefficient (ICC) was used to assess inter-observer conisitency of PAWPA measurements between two investigators who were blinded to each other's findings, and intra-observer consistency of PAWPA with repeating the measurements on two occasions by the same investigator in 20 randomly selected cases. Stepwise multiple regression was used to analyze the following potential influential factors of PAWPA: age, gender, heart rate, blood pressure, atherosclerosis, right atrial diameter, and pulmonary insufficiency. Results There was good consistency between two independent observers' measurements and between two occasions in the same observer's measurements for PAWPA with ICC values of 0.91 (95% CI, 0.37-0.99) and 0.95 (95% CI, 0.60-0.99), respectively. PAWPA was negatively correlated with age (β=-0.47, P<0.001) and heart rate (β=-0.29, P<0.005). There was no correlation of PAWPA with gender, blood pressure, atherosclerosis, right atrial diameter, and pulmonary insufficiency. Conclusion Anatomical M-mode echocardiography can be used for measuring PAWPA with good consistency and reproducibility. In normal pulmonary artery pressure cases, PAWPA is affected by age and heart rate.