Abstract: A modular bed frame includes two longitudinal members each having two opposite side walls. One side wall of each longitudinal member has a plurality of spaced-apart openings formed in an upper portion thereof. Lower portions of the two side walls of the longitudinal members are solid. A plurality of support bars are detachably connected between the longitudinal members. Each support bar has a bottom surface formed with two engaging slots proximate to two opposite end portions thereof. Each end portion of each support bar is inserted into one of the openings and then engaged to the lower portion through the engaging slot.