To investigate the effect of ultrasound and color Doppler flow imaging (CDFI) for differential diagnosing the early uterine cornual pregnancy (CP) and interstitial tubal pregnancy (ITP). Methods: The clinical data of 110 patients with ectopic pregnancy who were diagnosed by pathology in the hospital from January 2019 to October 2023 were analyzed retrospectively, including 52 patients with CP in group A and 58 patients with ITP in group B. The general information, the ultrasound features, and the CDFI parameters of the patients were compared between the two groups. Results: The proportion of the vaginal bleeding (90.4%) of the patients in group A was significantly higher than that (39.7%) of the patients in group B (P<0.05). The proportions of the intact uterine cavity (32.7%), the endometrial wrapping (82.7%) and the protruding gestational sac (23.1%) of the patients in group A were significantly lower than those (94.8%, 100.0% and 77.6%) of the patients in group B. The proportion of the intact peripheral muscle layer (94.2%) of the patients in group A was significantly higher than that (25.9%) of the patients in group B. The values of the thickness (6.20±1.65mm), the pulsatility index (1.25±0.35) and the resistance index (0.58±0.10) of the muscle layer around the gestational sac of the patients in group A were significantly higher than those (3.05±0.94mm, 0.97±0.23 and 0.49±0.08) of the patients in group B. The minimum end diastolic velocity (0.19±0.06) of the patients in group A was significantly lower than that (0.24±0.07) of the patients in group B (all P<0.05). Based on the results of pathology, the Kappa value, the sensitivity, the specificity and the accuracy of ultrasound and CDFI for differential diagnosing CP and ITP were 0.827, 88.46%, 77.59% and 82.73%, respectively. Conclusion: Vaginal ultrasound and CDFI have better differential diagnostic value for the early CP and ITP of the patients.