[Abstract] Objective: To summarize the ultrasonic characteristics of isolated tubal torsion and to improve the accuracy of diagnosis. Method: We retrospectively analyzed clinical characteristics, ultrasound diagnosis and surgical treatment of 7 cases of isolated fallopian tubal torsion, who were treated surgically in our hospital. Result: In all 7 cases of isolated fallopian tubal torsion, there were 2 cases in the left fallopian tube and 5 cases in the right fallopian tube. 2 cases had tubal mesangial cysts and 5 cases had hydrosalpinx. The twisted pedicle structure was found in totally 7 cases, of which 5 cases showed "vortex" sign and 2 cases showed slightly high echo nodules. In color doppler flow imaging, 5 cases had "vortex" blood flow in the pedicle, 2 cases had decreased arterial blood flow velocity in the pedicle, and 1 had no blood flow in the pedicle. Among these 7 cases, 4 cases formed "false bladder" signs because of abnormal tubal position, of which 2 cases had severe hydrosalpinx and 2 cases had tubal mesangial cysts. Conclusion: Isolated fallopian tubal torsion was often accompanied by hydrosalpinx or tubal mesangial cysts. The twisted pedicle structure in ultrasound was the direct diagnostic evidence for isolated fallopian tubal torsion. The disappearance of blood flow and the decreased arterial blood flow velocity in the pedicle may indicate necrosis of fallopian tube. The abnormal position of tube or tubal mesangial cysts was an important indirect sign of isolated fallopian tubal torsion.