A BOG re-liquefaction system of an LNG carrier is provided to reduce the amount of power and to make a smaller apparatus of a cooling cycle. A bog re-liquefaction system of an LNG carrier comprises the following: a BOG compressor(10) compressing the BOG; a first distributor(20) distributing and supplying the BOG generated by vaporizing LNG stored in a storage tank from the BOG compressor into a heat exchanger(40); and a second distributor(22) supplying a part of the compressed BOG into a DF engine and moving the rest from the heat exchanger to the storage tank.
