In a reclining structure (1, 21, 41, 61) according to the present invention, support members (2, 22, 42, 62), a seat member (3, 23, 43, 63) and a back member (5, 25, 45, 55, 75) are connected to one another freely with at least two kinds of members out of these support members, seat member and back member being joined together by a rod (11, 31, 51, 71) of a locking means (13, 33, 53, 73), the rod being disposed so as to cross one of these two kinds of members. These two kinds of members are locked so as not to be moved with respect to each other with a force imparted only between the rod-crossed member and rod. Accordingly, in order to re-adjust the reclining structure, a user changes his posture on a chair (1, 21, 61) or a bed (41) so as to release the rod-crossed member and rod from the force imparted therebetween and set the support members, seat member and back member, which constitute the reclining structure, freely movable. After the re-adjustment operation is finished, the user sits or lies on the seat member to cause the rod-crossed member and rod to be locked.