Abstract: Mortality rate of acute respiratory distress syndrome (ARDS) remains high despite the rapid development of treatment in the past fifty years. It is gradually discovered that not only lung injury but also circulatory changes in ARDS patients lead to right-ventricular (RV) failure and acute cor pulmonale (ACP). Short-term hypoxemia is not an independent risk factor. Pulmonary vascular dysfunction has been reported as an independent predictor of death in ARDS patients. As a result, core therapy in ARDS is gradually changed from lung protection to RV protection. In this paper, the characteristics of RV change and the strategies for RV protection in ARDS are reviewed. The existing problems with RV protection scheme are put forward. The concept of preemptive protection is proposed to provide new ideas for the treatment of ARDS in the future.