Objective To study the effect and safety sildenafil to pulmonary hypertension with congenital heart disease in children.Methods22 children with congenital heart disease were included in the study from Jan 2006 to Dec 2007. The PASP, HR, CO, LVEF and LVFS were studied after sildenafil administration. And the adverse effects of all children within 24 hours after sildenafil administration. ResultsOral sildenafil can decrease the PASP of PH with CHD and no apparent adverse effects were observed in all children after sildenafil administration.Conclusions Sildenafil is effective and safety for the treatment of PH with CHD.