The authors analyzed ultrasonographic findings of 112 cases of trophoblastic disases which were confirmed byD&E or hysterectomy at Wallace Memorial Baptist Hospital from September 1980 to December 1984. The results were asfollows; 1. Of all 112 cases, hydatidiform moles were 99 cases, invasive moles were 3 cases and choriocarcinomas were 10 cases. 2. 81 cases (72%) occurred in 3rd decades. 3. The sized of uterus was large for gestational weeksin 65 cases(56%) and smaller in 13 cases(13%). 4. The contour of uterus was globular in 59 cases(53%), diffuse in49 cases(44%) and nodular in 4 cases(3%). 5. The internal echopatterns of uterus revealed numerous small vesicular snowstorm patterns in all cases, and revealed internal degeneration in 67 cases(60%). 6. Uterine walls in 89 cases(79%) were well delineated but uterine walls in 23 cases(21%) were poor delineated. 7. Multiseptated ovarian thecalutein cysts were seen in 36 cases (32%). 8. Invasive trophoblastic disease(invasive moles 3 cases andchoriocarcinomas 10 cases) revealed similiar ultrasonographic findings with H-mole, but more irregular internalechoes and irregular echoes in uterine wall. 9. Diagnostic accuracy was diagnostic in 98 cases (88%) , nonspecificin 11 cases (10%) and error in 3 cases(2%).