Discussed is an organic electroluminescent device including a first charge carrying layer being disposed adjacent to a first electrode; and a second charge carrying layer disposed adjacent to a second electrode, wherein the first charge carrying layer includes an emitting part, a hole injection part and a hole transporting part between the hole injection part and the emitting part, wherein at least one of the hole injection part, the hole transporting part and the emitting part includes a host material having an organic compound of Formula: wherein R is substituted or non-substituted C1 to C12 alkyl, and A and B are symmetrically or asymmetrically positioned in 2-position or 7-position of the fluorene core, and wherein each of A and B is independently selected from substituted or non-substituted aromatic group or substituted or non-substituted heterocyclic group.