Background: Involuntary hospitalization (IH) is a controversial issue in psychiatry as it risks violation of the human right to autonomy. This study aimed to examine the rates and correlates of IH in a large psychiatric hospital from 2014-2017 after China’s Mental Health Law (MHL) was implemented in 2013 specifying criteria for IH and a structured assessment was required for IH.Methods: Unduplicated electronic medical records concerning all inpatients admitted to the Guangzhou Psychiatric Hospital with primary psychiatric diagnoses were examined and trends in annual IH rates were examined. We extracted medical, sociodemographic and socioeconomic data from these records to identify correlates of IH using bivariate chi square tests followed by logistic regression analysis. Results: Of 11,086 hospitalized patients, there was a significant but small increase from 71.6% to 74.9% in rates of IH in the years after the structured assessment was implemented. Logistic regression analysis showed IH was positively associated with being younger, having a local residence, and a diagnosis of bipolar disorder, schizophrenia spectrum disorders or a substance abuse disorder as compared to those diagnosed with major depressive disorder.Conclusions: Adjusting for these factors those with IH had a longer length of stays. Under China’s Mental Health Law in 2013, and a locally implemented checklist, the adjusted risk of IH increased significantly, but by only 3.3% from 2014 to 2017. IH was greatest younger patients with severe mental illnesses, and those with local access to psychiatric hospital services.