Abstract: A chair is provided with a seat, a chair back control unit, a chair back, and two armrest units. The chair back is pivotally coupled to the seat by sleeving the engaging portions of the seat onto the clamp members of the chair back. The assembling of the chair back onto the seat can be easily done by the actions of inserting and clamping, so that the assembly operation is quick and easy without using any screws, and therefore the assembly cost is reduced. Furthermore, the angle and height of the armrest units can be easily adjusted, and the chair back is foldable. With the abovementioned structural arrangements, the number of the parts of the chair is substantially reduced.

Abstract: A chair with a hip-shaping seat is provided with a base, a seat and two elastic members. The seat is formed by two seat members, and on the top of each of the seat members is formed an arc-shaped surface. The two seat members are pivoted connected at one end, and are capable of opening and closing at another end, so that the width of the seat space can also be adjusted to fit different sized hips, through pivoting of the seat members. Hence, the chair of the present invention is capable of effectively holding the hip and preventing the hip from sagging.

Abstract: A chair with a hip-shaping seat is provided with a base, a seat and two elastic members. The seat is formed by two seat members, and on the top of each of the seat members is formed an arc-shaped surface. The two seat members are pivoted connected at one end, and are capable of opening and closing at another end, so that the width of the seat space can also be adjusted to fit different sized hips, through pivoting of the seat members. Hence, the chair of the present invention is capable of effectively holding the hip and preventing the hip from sagging.