Objective To explore the hemodynamics changes of patent foramen ovale (PFO) ofnewborn and early infant.Methods Two groups of cases were analyzed in the study.One group was 60 cases of left-to-right(L-R)shunt in fossa ovalis(FO),the other group was 31 cases of PFO that were foundduring corrective heart surgery but no shunts in FO detected by echocardiography.ACUSON 128 was used.The main indexes were mobility of FO valve,phase,direction,velocity of shunt in FO,jet width.Results ①Valve of FO moved from left to right and right to left with the change of cardiac-period;②44 cages appeared that the jet with<5 mm,Doppler spectrum was two-peaks, positive continuity,peak flow velocity <0.5 m/s;③1 6 cases appeared that the jet width>6 mm,postive wide spectrum,continued from latesystole to diastole,peak flow velocity>0.6 cm/s;④Inside diameter in surgery group was 2～6 mm,meanvalue was 3.4 mm.Conelusions FO valves appears two-directional shunt,the PFO of newborn and early infant mostly appears left-to-right shunt.Atrial septal defect could be diagnosed when the jet width>6 mmand peak flow velocity>0.6 m/s.