This study determines the influence of lightning stroke current on 500 kV quadruple circuit transmission lines that will be used in Indonesia's power system. Analysis is conducted in ATPDraw and multistory model is used in modeling of transmission tower. Lightning induced voltage across insulator strings is the main factor being considered in this paper. Therefore, effect of varying lightning current stroke front time, magnitude of lightning stroke current, and tower grounding resistance to insulator voltage is being analyzed. This study is expected can be used as consideration in determining insulation coordination and designing protective device on 500 kV quadruple circuit transmission line.