The separator is an essential inactive component in liquid-electrolyte based batteries, with the function of separating the positive electrode from the negative electrode to avoid the electronic flow but enable the free ionic transport. The major commercial separators are thin, porous polymeric membranes with single layer or multilayers, and the polymer materials are typically polyolefins, polyesters, and so on. In recent years, separators with surface modifications have also been reported and produced for lithium (Li)-ion batteries, with the purposes of improving the mechanical strength, wettability, cell performance and safety tolerance under various abuse conditions. A lot of positive results have been achieved in Li-ion batteries. In recent years, with the demand for higher energy density than that from the state-of-the-art Li-ion batteries, the research and development of rechargeable Li metal batteries has been revived. However, the effects of the separators on the stability of Li metal anode and the performance of Li metal batteries have seldom reported. In this work, we have comprehensively studied the chemical and electrochemical stabilities of commercially available separators with Li metal anode in two kinds of liquid electrolytes, and found that the separators do have different stabilities with Li metal anode especially in conventional LiPF₆-based electrolytes. The details of the investigations will be reported at the presentation.