Provided are boron-containing polycyclic compounds of Chemical Formula 1: wherein X1 to X4 are identical to or different from one another and are each independently O, S, NR2 or CR3R4, and a to d are each 0 or 1, with the proviso that 1≤a+b+c+d, and the other substituents are as described in the specification. The compounds have a high electron accepting ability and excellent heat resistance, and can be highly purified by sublimation purification due to their high sublimation temperature. The compounds can form a stable interface with an electrode or an adjacent organic material layer of an organic light emitting device. Also provided is an organic light emitting device including the compound of Chemical Formula 1. The compound can lower driving voltage and lengthen lifetime of the organic light emitting device.