ObjectiveTo investigate ultrasonographic characteristics and diagnostic approaches of unruptured tubal pregnancy (UTP).MethodsOne hundred forty-six cases of early tubal pregnancy, which were confirmed surgically, were analyzed.ResultsAmong 146 cases of UTP, 130 were diagnosed by ultrasonography. Furthermore, 16 cases of UTP were missed by ultrasonography. A total of 130 patients had a mass detected by ultrasonography, among whom the mass and ipsilateral ovary were distinguishable in 102. The embryo sac type was found in 40.00% (52/130), while the heterogeneous mass type was found in 60.00% (78/130) of patients. The maximum length and diameter of the ectopic pregnancy mass ranged from 10 to 68 mm (mean size, 26.42 ± 11.39 mm). No blood flow was observed in or around the mass in 67.69% (88/130) of patients. Lateral tubal thickening of the mass was found in 47.69% (62/130) of patients. Endometrial thickness was ≤10 mm in 67.80% (99/146) of patients. The intima was mostly hyperechoic in 72.60% (106/146) of patients.ConclusionA paraovarian mass, thickened fallopian tube, uterine endometrium with a thickness of ≤10 mm, and high echo are important indicators of early UTP. Ultrasound examinations should focus on these indicators to help improve detection of early tubal pregnancy.