The reactions of selected triterpenic oxo compounds with Lawesson's reagent were investigated. We examined sulfurization of some oxygen compounds and for these reactions several hinderedketones, one aldehyde, α-hydroxyketones, esters, or anhydrides were chosen. We synthesized 15 new sulfur derivatives, including thioketone 16, dimeric sulfides 17–19, and thiaderivatives 20–22. We also observed unusual