High current discharge experiments were conducted on the gas spark gaps（GSGs） with Mo

WCu

and W for their main electrode materials to investigate the variation of three GSGs’ electrical performances with discharge number.Experimental results indicate that with discharge number increases

the self-breakdown voltages of three GSGs decrease and minimum working voltages increase.A great number of cracks

erosion craters and saliences are observed on the surfaces of the electrodes.Among three GSGs

the GSG with W-electrode exhibits steady electrical performance during multiple discharge process and the longest lifetime;the GSG with Mo-electrode shows clear undulation of the electrical performance and the shortest lifetime;and the GSG with WCu alloy-electrode exhibits elevated and undulating lower-limit working voltage

steady self-breakdown voltage

and longer lifetime.Therefore

tungsten with excellent anti-erosion performance could be selected as the preferred electrode material for GSG.