A luminescent spiro-dimer which has a superior heat-resistance and is capable of emitting high quality blue light, and an organic light-emitting device including the same are disclosed. The luminescent spiro-dimer has the structure of the following chemical formula, and the organic light-emitting device includes the first electrode having a high work function; the second electrode having a low work function; and at least one organic layer formed between the first electrode and the second electrode, which includes the spiro-dimer, wherein, K is a linking group, and R is H, halogen, CN, CO2R*, OR*, NR*2, SR*, alkyl, aryl, heteroaryl, heterocyclic or fused ring group, and R* is H, halogen, alkyl, alkenyl, aryl, heteroaryl, or heterocyclic group.