Objective To investigate ultrasonographic characteristics and diagnostic approaches of unruptured tubal pregnancy (UTP). Methods One hundred forty-six cases of early tubal pregnancy, which were confirmed surgically, were analyzed. Results Among 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. Conclusion A 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.