A lumbar support structure comprises: a lumbar pad two circling knee devices, disposed at two sides of the lumbar pad, each possessing a first strip member and a second strip member two knee pads, movably female-connected with the first strip members, each possessing a penetrating portion with a through channel, the first strip member and the knee pad fabricating a knee-binding structure two adjustment buckles, each disposed between the first strip member and the second strip member, a front end of the adjustment buckle being fastened with the first strip member, the second strip member penetrating through the adjustment buckle and elongating toward the lumbar pad in order to form an embracing portion, wherein the embracing portion elongates toward the lumbar pad in order to form a movable adjustment band.
