Aim To explore the influencing factors of fat attenuation index of pericoronary adipose tissue (FAI-PCAT) when there is no local inflammation or mild inflammation of coronary artery, and to establish a regression model to predict the individual baseline values of FAI-PCAT. Methods Hospitalized patients who had no previous history of coronary heart disease and underwent coronary computed tomography angiography (CCTA) examination to exclude obstructive coronary artery disease in the First Affiliated Hospital of Harbin Medical University from January to December 2019 were included. The baseline data and clinical indexes such as sex, age, height, weight, past medical history, blood routine, blood glucose, and blood lipid were collected. The AW VolumeShare 4 CT working software was used to post-process the CCTA images by one doctor with more than 3 years of imaging experience, and FAI-PCAT and epicardial fat attenuation (EFat) were measured and recorded. Spearman correlation was used to analyze the correlation of factors. Multiple linear regression was used to analyze the influencing factors of FAI-PCAT and then established a regression model. Results A total of 103 patients with CCTA showing CAD-RADS 0～1 were included. The FAI-PCAT value is (－82.2±7.0) Hu, the EFat value is (－84.8±4.4) Hu. Correlation analysis showed that FAI-PCAT was significantly and positively correlated with EFat (P＜0.01), significantly and negatively correlated with lymphocyte to monocyte ratio (LMR), lymphocyte percentage (P＜0.01), and positively correlated with blood glucose level (P＜0.05). There was no correlation between FAI-PCAT and body mass index (BMI), blood lipid. The EFat was significantly and negatively correlated with BMI, triglyceride (TG), low density lipoprotein cholesterol/high density lipoprotein cholesterol (LDLC/HDLC), very low density lipoprotein cholesterol (VLDLC) (P＜0.01), and significantly and positively correlated with HDLC (P＜0.01), positively correlated with apolipoprotein A/apolipoprotein B (ApoA/ApoB) (P＜0.05). Multiple linear regression analysis showed that EFat value (X₁), LMR (X₂), and blood glucose level (X₃) were the main influencing factors and prediction parameters of FAI-PCAT value when there was no local inflammation or mild inflammation of coronary artery, and the regression equation was =－25.466+0.686X₁－0.9X₂₊₁.207X₃. Conclusion EFat value, LMR, and blood glucose level were the main influencing factors of FAI-PCAT value when there was no local inflammation or mild inflammation of coronary artery, and the regression model can predict the individual baseline values of FAI-PCAT.