Objective     To investigate activated toll-like receptor-4 (TLR4) signaling pathway involved in pathophysiological mechanisms of type A aortic dissection (TAAD). Methods     Specimens of full-thickness ascending aorta wall from the TAAD patients (n=12) and the controlled donors (n=12) were collected. Western blotting was used to examine the associated proteins' expression of TLR4 signaling pathway. Blood samples from TAAD (n=43) and controlled patients (n=50) were examined by enzyme-linked immunosorbent assay (ELISA) to detect the circulating plasma cytokines levels of interleukin-1β (L-1β). Results     In the aortic wall of TAAD, expression levels of TLR4 and protein expression of major molecule significantly elevated, and activated macrophages increased. Furthermore, elevated IL-1β levels were observed in the TAAD patients’ plasma compared with the control plasma. Multiple logistic regression analysis and receiver operating characteristic (ROC) curve showed that elevated IL-1β could be a novel and promising biomarker with important diagnostic and predictive value in the identification of TAAD. Conclusion     Activated TLR4/NF-κB signaling pathway regulates inflammatory response to involve in pathophysiological mechanisms of type A aortic dissection and its regulated inflammatory products have important predictive value for patients with TAAD.