A bed base capable of fixing mattress includes a base frame and a fixation member. The base frame includes at least one insertion hole. The fixation member includes at least one horizontally extended part, at least one insertion part downwardly extended from an end of the horizontally extended part, and a stopper part upwardly extended from the other end of the horizontally extended part. The insertion part is inserted into the insertion hole of the base frame, the horizontally extended part is placed on a top surface of the base frame, and the stopper part is used to stop at a side edge of the mattress. Therefore, the assembly or disassembly of the fixation member can be achieved without tool assistance.