Chemistries of sulfur and sulfur-containing silane coupling agent as important materials in rubber manufacture are discussed directed toward the understanding of fundamental property of sulfur chains. In relation to polymeric sulfur insoluble in carbon disulfide which is used as a key material for crosslinking of tire rubber, basic property of sulfur and chemistry of sulfur chain involving more than two sulfur atoms are introduced, where instability of oligosulfide is emphasized under both radical and ionic reactions. Chemistry of oligosulfide linkage of silane coupling agents used for automobile tires reinforced by silica is effectively contributed to the development of the new manufacturing method of the silane coupling agent at 2000.