Provided are a transition metal compound including a novel carbene compound as a ligand, a preparation method thereof, and an application thereof. The transition metal compound according to the present invention may form a structurally stable complex and also have a HOMO-LUMO energy gap and singlet-triplet transition energy which are significantly low as compared with a conventional transition metal compound. In addition, according to the present invention, the transition metal compound may be synthesized in large quantities by a very simple method, thereby having high commercial utility, and thus, an application using the compound is expected.