An organic light emitting device comprising: an anode; a cathode that is provided opposite to the anode; and a light emitting layer that is provided between the anode and the cathode wherein the light emitting layer comprises a first compound represented by the following Chemical Formula 1 and a second compound represented by the following Chemical Formula 2: in the Chemical Formula 1, A is substituted or unsubstituted carbazolyl, L 1 is a single bond, or substituted or unsubstituted C 6-60 arylene, X 1, X 2 and X 3 are each independently N, or CH, provided that at least one of X 1, X 2 and X 3 is N, and Ar 1 and Ar 2 are each independently substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, in the Chemical Formula 2, B is a benzene ring fused with two adjacent pentagonal rings, L' 1 and L' 2 are each independently a single bond, or substituted or unsubstituted C 6-60 arylene, Ar' 1 and Ar' 2 are each independently substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, R' 1, R' 2 and R' 3 are each independently hydrogen, deuterium, substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, a is an integer of 0 to 4, b is an integer of 0 to 2, and c is an integer of 0 to 4. an anode; a cathode that is provided opposite to the anode; and a light emitting layer that is provided between the anode and the cathode wherein the light emitting layer comprises a first compound represented by the following Chemical Formula 1 and a second compound represented by the following Chemical Formula 2: in the Chemical Formula 1, A is substituted or unsubstituted carbazolyl, L 1 is a single bond, or substituted or unsubstituted C 6-60 arylene, X 1, X 2 and X 3 are each independently N, or CH, provided that at least one of X 1, X 2 and X 3 is N, and Ar 1 and Ar 2 are each independently substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, in the Chemical Formula 2, B is a benzene ring fused with two adjacent pentagonal rings, L' 1 and L' 2 are each independently a single bond, or substituted or unsubstituted C 6-60 arylene, Ar' 1 and Ar' 2 are each independently substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, R' 1, R' 2 and R' 3 are each independently hydrogen, deuterium, substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, a is an integer of 0 to 4, b is an integer of 0 to 2, and c is an integer of 0 to 4. A is substituted or unsubstituted carbazolyl, L 1 is a single bond, or substituted or unsubstituted C 6-60 arylene, X 1, X 2 and X 3 are each independently N, or CH, provided that at least one of X 1, X 2 and X 3 is N, and Ar 1 and Ar 2 are each independently substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, in the Chemical Formula 2, B is a benzene ring fused with two adjacent pentagonal rings, L' 1 and L' 2 are each independently a single bond, or substituted or unsubstituted C 6-60 arylene, Ar' 1 and Ar' 2 are each independently substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, R' 1, R' 2 and R' 3 are each independently hydrogen, deuterium, substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, a is an integer of 0 to 4, b is an integer of 0 to 2, and c is an integer of 0 to 4. B is a benzene ring fused with two adjacent pentagonal rings, L' 1 and L' 2 are each independently a single bond, or substituted or unsubstituted C 6-60 arylene, Ar' 1 and Ar' 2 are each independently substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, R' 1, R' 2 and R' 3 are each independently hydrogen, deuterium, substituted or unsubstituted C 6-60 aryl, or substituted or unsubstituted C 2-60 heteroaryl containing at least one heteroatom selected from the group consisting of N, O and S, a is an integer of 0 to 4, b is an integer of 0 to 2, and c is an integer of 0 to 4.