Objective: To investigate the association between serum sex hormone-binding globulin (SHBG) and non-alcoholic steatohepatitis (NASH). Methods: In this cross-sectional study, a total of 371 middle-aged and young obese patients who were hospitalized and underwent liver puncture in Nanjing Drum Tower Hospital from January 2016 to April 2021 were included. The population was divided into control group (n=43) and non-alcoholic fatty liver disease (NAFLD) group (n=328) based on the non-alcoholic fatty liver disease activity score. Subjects in NAFLD group were further divided into non-alcoholic fatty liver (NAFL) (n=60), uncertain-NASH (n=172), and NASH (n=96). Serum SHBG was tested in patients with NAFLD who were divided into three subgroups according to tertiles. The liver pathological characteristics in different SHBG level subgroups were compared. The risk factors of NASH were analyzed by logistic regression. The prediction model of NASH noninvasive diagnosis was established by forward stepwise regression, and the diagnostic value of non-invasive model for NASH was evaluated by receiver operating characteristic (ROC) curve. Results: The median age in patients were (32±10) years old with a body mass index of (39.16±6.58) kg/m², including 236 females (63.6%). Serum SHBG level [M (Q1, Q3)] in NAFLD group was significantly lower than that in control group [16.90 (11.43, 23.00) vs. (23.45 (15.40, 31.22) mmol/L, P<0.05], and progressively diminished in NAFL, uncertain-NASH and NASH subgroups [(22.24±10.47), (20.57±19.58), (15.80±8.74) mmol; P for trend<0.05]. Compared with the high-leveled SHBG subgroup, the steatosis score (2.09±0.80 vs. 1.51±0.72, P<0.01) and lobular inflammation score (1.10±0.68 vs. 0.85±0.68, P<0.05) were significantly higher in the low-leveled SHBG group. Multivariate logistic regression analysis indicated that lower serum SHBG level was an independent risk factor for NASH (OR=2.527, 95%CI: 1.296 to 4.928, P<0.05). The area under ROC curve of SHBG combined with aspartate aminotransferase in predicting NASH in NAFLD patients was 0.752 (95%CI: 0.696 to 0.809). Conclusion: Low serum SHBG level is associated with NASH.