A hinge assembly is provided for hingedly connecting a first frame to a second frame, and includes at least one hinge module which includes a first mounting base, a first connection member, a second connection member, and a transmission unit. The first and second connection members are coupled to the first and second frames, respectively, and are turnably mounted to the first mounting base respectively about first and second turning axes which are parallel to and offset from each other. The transmission unit is provided to permit the first and second connection members to turn in opposite rotational directions from each other whilst turning simultaneously.