A heat spreader structure and a manufacturing method thereof. The heat spreader structure includes a main body. The main body includes a first board body and a second board body corresponding to the first board body. The second board body is mated with the first board body to form the main body. The main body has a circulation area and a connection area. The circulation area is connected with the connection area to together define a chamber in which a working fluid is contained. The circulation area has a first capillary structure, while the connection area has a second capillary structure. In manufacturing, the heat spreader structure can be freely bent and shaped without damaging the internal capillary structures.