Abstract: Objective To explore the clinical value and influencing factors of noninvasive ultrasound attenuation imaging (ATI) in the diagnosis of metabolic fatty liver disease (MAFLD).Methods 122 subjects were recruited from the physical examination department, hepatology department and endocrinology department of our hospital for a prospective study. They were divided into 31 healthy volunteers (normal control group) and 91 patients with MAFLD (MAFLD group). All subjects were examined by abdominal two-dimensional ultrasound, ATI, controlled attenuation imaging (CAP) and serology. The differences of the above indicators between the two groups were compared. Based on the results of CAP examination, the ROC curve of subjects was drawn to analyze the efficacy of ATI in the diagnosis of fatty liver at different levels, and the correlation between ATI and CAP, ATI and two-dimensional ultrasound grading in the diagnosis of fatty liver, as well as the influence of various clinical data on the attenuation coefficient (AC) value.Results There were significant differences in body mass index, triglyceride, alanine aminotransferase and glutamic oxaloacetic transaminase between MAFLD group and normal control group (all P＜0.05). The AC value of MAFLD group was (0.79 ± 0.11) dB · cm-1 · MHz-1, which was higher than that of healthy control group (0.58 ± 0.45) dB · cm-1 · MHz-1. The AC value increased with the increase of fatty liver degree, and the difference was statistically significant (all P＜0.05). ROC curve analysis showed that the cutoff value of AC value in diagnosis of ≥ S1, ≥ S2, ≥ S3 fatty liver was 0.64, 0.70, 0.79 dB · cm-1 · MHz-1, the sensitivity was 89.7%, 80.6%, 100%, and the specificity was 90.3%, 69.0%, 87.1%, respectively. Coherence analysis showed that ATI was positively correlated with CAP, ATI with two-dimensional ultrasound grading in the diagnosis of MAFLD (r=0.940, 0.851, all P＜0.0001); Multivariate linear regression analysis showed that the change of AC value was not affected by clinical data, but only related to the degree of fatty liver. Conclusion ATI technology has good diagnostic efficacy in diagnosing MAFLD and its degree grading, and is significantly related to CAP and two-dimensional ultrasound grading, and the change of AC value is not affected by clinical parameters, but only related to the degree of fatty liver.