The present invention is a massage chair, having main frame with specific curve, a chair back located by the chair seat, wherein the chair back is adjusted properly by the chair seat for rotating and having 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 degrees.