【Abstract】Objective To reseavch the value of fullvocume of threedinlensional echocor diography in diagnosis and treafmenf of children ventricular sepfal defecf. Methods 35 patients with ventricular septal defect were treated with two dimensional (2D) and full volume three-dimensional ultrasound. The clinical data were analyzed.Results There were no statistical differences between the two group of measurements and ventriculography or the diameter of occluder respectively (P>0.05). FV3DE had a better relation with the ventriculography (r=0.781, P＜0.05) than 2DE (r=0.617, P＜0.05). FV3DE had a moderate relation with the diameter of occluder (r=0.411, P＜0.05). There were no relations between the results measured by 2DE and the diameter of the occluder (P=0.075). There were 5 of 33 points(15.2%) were out of the 95% limits of agreement in the difference between ventriculography and 2DE. However, of difference between ventriculography and FV3DE, there were only 2 of 33 points (6.1%)were out of the 95% limits of agreement. In the difference between the diameter of occluder and 2DE, the points out of the 95% limits of agreement were account for 12.1%(4/33). However, there were 2 of 33 points (61%) were out of the 95% limits of agreement in the difference between the diameter of occluder and FV3DE. The area of VSDs appeared maximal in the early systolic phase and minimal in the endsystolic phase. Conclusion Full volume realtime threedimensional echocardiography can accurately assess the shape and size of the ventricular septal defect and provide more comprehensive information for clinical treatment.