A dynamic random access memory (DRAM) is provided. The DRAM comprises a substrate, a plurality of isolation structures, a plurality of word lines, a plurality of bit line contacts and a plurality of buried bit lines. The isolation structures are located in the substrate and defines a plurality of active regions extending along a first direction. The word lines are located in the substrate and are extending along a second direction, the second direction intersects with the first direction. The bit line contacts are located above the isolation structures, wherein each of the bit line contacts have a diffusion region that defines a bit line side contact. The buried bit lines are located above the bit line contacts and are connected to the active region via the bit line side contact, the buried bit lines are extending along the first direction and is parallel with the plurality of active regions.