Abstract: A chair includes a stand, a support base mounted on the stand, a backrest mounted on the support base, a fixed bracket pivotally mounted on the support base, a movable bracket movably mounted on the fixed bracket, and a seat mounted on the movable bracket to move with the movable bracket. Thus, when the movable bracket is unlocked from the fixed bracket, the movable bracket is movable relative to the fixed bracket so that the seat is movable relative to the stand and the backrest to adjust the position of the seat relative to the stand and the backrest according to a user's requirement, thereby providing a comfortable sensation to the user.