<p>Background: We sought to establish a prospective hospital-based cohort, featuring detailed multidimensional data of trauma patients with active follow-ups, which can be a reliable data source for all studies focusing on the effects or underlying mechanistic pathways of environmental and biological factors on multiple interested trauma-related outcomes, particularly the incidence and trajectory of trauma-related psychopathology, in a Chinese population.</p><p>Methods: The China Severe Trauma Cohort (CSTC) enrolled all traumatized individuals aged 12 to 80 years admitted to the Trauma Center of West China Hospital between March 1^st, 2020 and July 8^th, 2022. The bio-sample and detailed questionnaire data were collected at recruitment, and phone/internet follow-ups were scheduled at 1, 3, 6, and 12 months after the baseline. Long-term health outcomes are planned to be obtained from administrative databases through data linkage.</p><p>Results: A total of 2,500 trauma patients were enrolled (response rate = 87.1%) with an average age of 46.01 years, and most of the participants were males (62.6%). The proportions of participants with blood and fecal sample collected at baseline were 93.8% and 66.3%, respectively. As of August 31^st, 2022, the follow-up rate was 90.0%, 77.0%, 76.5%, and 89.0% for 1-, 3-, 6-, and 12-month follow-ups, respectively. Fall/wrench (47.6%) and traffic accident (26.2%) were the top causes of current trauma. The most common psychopathology at recruitment was sleep disturbance (39.4%), followed by depression (22.6%), anxiety (18.2%), and acute stress reaction (7.8%), all of which showed recovering trajectories during the follow-up period, particularly the first 3 months after baseline.</p><p>Conclusion: CSTC provides a platform with multidimensional data to study both short-term and long-term trauma-related health consequences, prompting early identification and intervention for individuals with high risk of health decline after trauma exposures.</p>