Positioning structure

A positioning structure adapted for installing and fixing at least two storage devices having different sizes, wherein each of the storage devices has a plugging end and a fixing end opposite to the plugging end, the positioning structure comprising:

• a casing;
• a socket, disposed on the casing, wherein the plugging end of the each of the storage devices is adapted to be plugged into the socket;
• at least two position-limiting components, protruding from the casing and located on a same side of the socket, wherein the at least two position-limiting components are L-shaped hooks and are unitarily formed on the casing, one of the position-limiting components keeps a first distance from the socket, and the other of the position-limiting components keeps a second distance greater than the first distance from the socket;
• and
• a fixing bracket, detachably engaged with the position-limiting component keeping the first distance from the socket, so that the fixing end of the storage device having a smaller size is fixed to the fixing bracket, or the fixing bracket, detachably engaged with the position-limiting component keeping the second distance from the socket, so that the fixing end of the storage device having a bigger size is fixed to the fixing bracket.