Our study aims at comparative research of the holidays dedicated to Demetrius at Megara and its pontic colonies (Byzantion, Mesambria, Callatis). At Megara and in the Pontic Megarian colonies, Demetra was adored with a multitude of epicleses: Thesmophoros, Malophoros, Chthonia, Ploutodoteira. The holidays dedicated to Demetrius (Chthonia, Thesmophoria, Malophoria) in the Pontic Megarian fortresses have an agrarian character. On this occasion, Demetra was celebrated in the hypothesis of Chtonian deity and goddess of the fertility of the land and of agriculture. Pontic colonies of Megarian origin have adopted the holiday cycle set by the Megarian tradition.