p-Hydroxybenzoic acid, which is one of the precursors in shikonin biosynthesis, and its glucoside ( p- O-β- D-glucosylbenzoic acid) were isolated from the cell cultures of Lithospermum erythrorhizon. The glucoside was accumulated by the cells producing no shikonin in LS liquid medium, but it decreased rapidly when the cells were transferred to “production medium” to induce shikonin synthesis. These results suggest that the precursor p-hydroxybenzoic acid is stored in the form of a glucoside when the cells are not synthesizing shikonin.