A functional chair comprising acupressure balls, comprising: a chair seat; a back of a chair coupled to one side of the chair seat and extended in the upward direction; a pair of acupressure plate rotary shafts which is parallel to a vertical axis at a position ambilaterally spaced at a predetermined distance from the center of rear surface of the back of the chair; a pair of acupressure plates which rotate around the respective acupressure plate rotary shafts; and a pair of armrests coupled and fixed to one side of the respective acupressure plates, and extended to the front of the back of the chair, wherein: a plurality of operating holes formed by being perforated on the front of the back of the chair at symmetrical positions of both right and left sides based on the vertical axis of the center of the back of the chair are further comprised; a sleeve for covering the acupressure plate rotary shaft is positioned along a lengthwise direction on the respective acupressure plates, and the acupressure plate rotary shaft penetrates the sleeve such that the respective acupressure plates is rotatably fixed to the respective acupressure plate rotary shafts; a plurality of horizontal extension parts are provided on the respective acupressure plates and extended at a certain length in a perpendicular direction of the sleeve, acupressure ball mounting parts for fixing acupressure balls are provided at the end of the respective horizontal extension parts, and acupressure balls are rotatably fixed in the respective acupressure ball mounting parts; and as the armrests and the acupressure plates rotate on the respective acupressure plate rotary shafts, the plurality of horizontal extension parts and the acupressure balls fixed to the ends of the respective horizontal extension parts protrude to and retract from the front of the back of the chair through the operating holes corresponding to the respective acupressure balls. a chair seat; a back of a chair coupled to one side of the chair seat and extended in the upward direction; a pair of acupressure plate rotary shafts which is parallel to a vertical axis at a position ambilaterally spaced at a predetermined distance from the center of rear surface of the back of the chair; a pair of acupressure plates which rotate around the respective acupressure plate rotary shafts; and a pair of armrests coupled and fixed to one side of the respective acupressure plates, and extended to the front of the back of the chair, wherein: a plurality of operating holes formed by being perforated on the front of the back of the chair at symmetrical positions of both right and left sides based on the vertical axis of the center of the back of the chair are further comprised; a sleeve for covering the acupressure plate rotary shaft is positioned along a lengthwise direction on the respective acupressure plates, and the acupressure plate rotary shaft penetrates the sleeve such that the respective acupressure plates is rotatably fixed to the respective acupressure plate rotary shafts; a plurality of horizontal extension parts are provided on the respective acupressure plates and extended at a certain length in a perpendicular direction of the sleeve, acupressure ball mounting parts for fixing acupressure balls are provided at the end of the respective horizontal extension parts, and acupressure balls are rotatably fixed in the respective acupressure ball mounting parts; and as the armrests and the acupressure plates rotate on the respective acupressure plate rotary shafts, the plurality of horizontal extension parts and the acupressure balls fixed to the ends of the respective horizontal extension parts protrude to and retract from the front of the back of the chair through the operating holes corresponding to the respective acupressure balls. a plurality of operating holes formed by being perforated on the front of the back of the chair at symmetrical positions of both right and left sides based on the vertical axis of the center of the back of the chair are further comprised; a sleeve for covering the acupressure plate rotary shaft is positioned along a lengthwise direction on the respective acupressure plates, and the acupressure plate rotary shaft penetrates the sleeve such that the respective acupressure plates is rotatably fixed to the respective acupressure plate rotary shafts; a plurality of horizontal extension parts are provided on the respective acupressure plates and extended at a certain length in a perpendicular direction of the sleeve, acupressure ball mounting parts for fixing acupressure balls are provided at the end of the respective horizontal extension parts, and acupressure balls are rotatably fixed in the respective acupressure ball mounting parts; and as the armrests and the acupressure plates rotate on the respective acupressure plate rotary shafts, the plurality of horizontal extension parts and the acupressure balls fixed to the ends of the respective horizontal extension parts protrude to and retract from the front of the back of the chair through the operating holes corresponding to the respective acupressure balls.