Pulmonary valvular resistance (PVR) of 40 children with pulmonary valvular stenosis was determined by color Doppler echocardiography before and after percutaneous balloon pulmonary valvuloplasty as well as during their follow-up. The correlation coefficient of PVR between Doppler method and catheterization method was 0.85 ( P <0.01) and the correlation coefficient between PVR determined by former method and pulmonary valvular area determined by the latter was -0.80 ( P <0.01). This study indicates that color Doppler echocardiography can take the place of catheterization to determine PVR in assessing the severity of pulmonary valvular stenosis in children.