An improved memory module structure includes a printed circuit board, memory units disposed on the printed circuit board, and a connection interface disposed on the printed circuit board for connection with an electronic device. The printed circuit board includes a solder pad zone having solder pads electrically connected with the memory units and the connection interface. A conduction element is combined with the solder pad zone or at least one conductor line electrically connected, in the form of bridge connection, the solder pads, in order to have the solder pads electrically connected. A memory module modification method is also provided, including removing a register from an existing dual inline memory module to expose a solder pad zone, and disposing of a conduction element or arranging a conductor line to have the memory units and the connection interface of electrically connected to thereby form an improved memory module structure.