ObjectiveTo summarize the ultrasonographic characteristics of cornual and intramural pregnancy and evaluate its value on differential diagnosis.MethodsIn all 89 patients, the diagnosis was confirmed at surgery and histologic evaluation, including 48 cases of cornual pregnancy and 41 cases of intramural pregnancy.And the ultrasound findings of those patients were retrospectively analyzed.ResultsBoth ectopic pregnancies presented a gestational sac or a pregnancy lump in the uterine horn, or in the adnexa area near the uterine horn on ultrasonography.No significant differences between cornual pregnancy and intramural pregnancy were found in the notch of pregnancy lump and uterine horn, the adjacent relation between lump and uterine cavity, and the sign of interstitial\|line(P>0.05), whereas more intact muscularis around the pregnancy lump was found in cornual pregnancy than in intramural pregnancy(χ2=5.27，P<0.05).Patients who had uterine curettage under ultrasonographic guidance or laparoscopic surveillance showed a slightly thick and intact muscularis around the pregnancy lump in comparison to those who underwent embryo removal surgery, cornual or interstitial tubal resection （χ2=15.63，P<0.05）.ConclusionA intact uterine muscularis around the pregnancy lump is the key point for differential diagnosis of cornual pregnancy and intramural pregnancy.And a slightly thick muscularis around the lump is one of the main indications for uterine curettage.