Disclosed herein is an LNG transferring arm. The LNG transferring arm includes a cylindrical support base. A main body is rotatably provided on the support base. A boom assembly is connected to a side of the main body to rotate up and down. A support assembly supports the boom assembly and is bent along with the boom assembly. A transfer pipe and a return pipe are arranged along the boom assembly. An end of each of the transfer pipe and the return pipe is connected to a tank to which LNG will be transferred. A balance weight is rotatably supported above the main body via a bracket, and is hinged at one end thereof to the boom assembly, thus maintaining balance. A rotary branch means is provided in the main body, and includes two pipes having different diameters and arranged concentrically.