Abstract: OBJECTIVE To explore the effects of conventional ultrasound and contrast-enhanced ultrasound on differential diagnosis of patients with liver abscess. METHODS The clinical data of 104 patients with liver abscess who were treated in General Hospital Affiliated to Tianjin Medical University from Jul 2017 to Feb 2018 were retrospectively analyzed, the patients were divided into the conventional ultrasound group with 48 cases and the ultrasound contrast group with 56 cases according to the type of ultrasound used before surgery. The clinical data of the patients were compared, the rates of accurate diagnosis of different stages of liver abscess were statistically analyzed, and the imaging characteristics of the contrast-enhanced ultrasound patients with different phases of liver abscess, including high enhancement of arterial phase, low enhancement of portal venous phase and delayed phase and enhancement in display range were observed. RESULTS There were no significant differences in the clinical data such as gender, age, disease course, number of lesions, clinical symptom and phase of liver abscess between the two groups of patients. The rate of accurate diagnosis of lesions of the ultrasound contrast group was 94.64%, higher than 79.17% of the conventional ultrasound group, the rates of accurate diagnosis of abscess of inflammatory stage, abscess of preliminary formation stage and abscess of formation stage were significantly higher in the ultrasound contrast group than in the conventional ultrasound group (P＜0.05). The percentage of the patients who had abscess of formation stage of high enhancement of arterial phase was the highest (93.10%) in the ultrasound contrast group, the percentage of the patients who had abscess of inflammatory stage of low enhancement of portal venous phase and delayed phase was the highest (100.00%), the percentage of the patients who had abscess of preliminary formation stage of enhancement in display range was the highest (94.12%), and there was significant difference (P＜0.05). CONCLUSION The patients with different stages of liver abscess who receive the contrast-enhanced ultrasound examination show various imaging characteristics, which may help clinicians to diagnose the abscess; the rate of accurate diagnosis of the contrast-enhanced ultrasound is remarkably higher than that of the conventional ultrasound, and it is worthy to be promoted in hospitals.