summary: Sepsis is a life-threatening organ dysfunction caused by the imbalance of the host's response to infection such as bacteria. The progress of the disease depends on the systemic inflammatory response, which is closely related to the host's immunosuppression. It is one of the most common clinical severe diseases. In order to deeply explore the potential core mechanism of sepsis, this study uses modern high-throughput technology to detect the peripheral blood samples of patients with sepsis and the control group, and intends to construct the biological information of sepsis system. The samples of the project were collected within 24 hours after being admitted to the ICU / EICU of the Affiliated Hospital of Southwest Medical University from January 2019 to January 2020. The first batch of analysis is sepsis (n = 23) vs NC (n = 10); The second batch was sepsis (n = 32) vs SIRS (n = 13). Sepsis patients were diagnosed by sepsis 3 0 standard (2016), i.e. infection + △ sofa ≥ 2; Sirs patients were other patients admitted to ICU at the same time (post-traumatic surgery or other). The peripheral blood samples of each patient (qualified in quality control) were analyzed by RNA sequencing (mRNA / lncrna / circrna), microRNA sequencing and metabolic mass spectrometry. All cases were signed by patients or their relatives to ensure informed consent for inclusion in the study; This experiment passed the ethics committee of the Affiliated Hospital of Southwest Medical University (ethics number: ky2018029), and the clinical experiment registration number is chictr190021261. The multi omics analysis part is divided into two parts: conventional difference screening part (left) and specific target factor expression retrieval (right)