The present invention is a massage chair, having a main frame with specific curve, a chair back located by a chair seat with a rotation angle wherein the main frame including back section, buttock section and leg section, the buttock section has an upward curve and the leg section has a downward curve, thus, massage provider can provide massage service to human thigh when the rotation angle is more than 110 degree a seat supporter is restricted by a restriction supporter, then the rotation angle is smaller as a first rotation supporter rotates counter-clockwise and the main frame rotates clockwise, wherein the seat supporter is disposed within the chair seat, and the first rotation terminal is disposed under the main frame.