The invention provides a structure of side part of a bed, by which a bed can be low and a user and operation of a nurser are not influenced, wherein the structure can be easily used for accommudating a side hand rail. The In the side structure of the bed, the bed (1) of the mattress (2) having a side portion of the side railing (4) and having a support member (7), which is used to support the side railing (4) and having one end side and placing the mattress (2) of the floor portion (3) side connected to the other end side of the side railing (4) side connection, whereby the side railing (4) can be moved to the mattress (2) above and below the mattress (2). As a side railing (4) of the structure, to move the mattress under (2) above state, the side railing (4) of the lower edge (4d) arranged in the mattress (2) of the lower side of the mattress to move (2) the state of the bottom, side railing (4) of the upper end portion (4c) arranged in the mattress (2) on the lower side.
