The invention provides a back of chair massage device. The back of chair massages device changes the relative standout between two massage elements and the relative distance between upper and lower part using an improved swing and setting mechanism, transforms two wheels or four wheels massage elements operation using said swing and setting mechanism, and changes the state of force when finger pressing, kneading, beetling massage to meeting the needs of users. It can simulate human nail pressing and rubbing massage matching relative standout degree between a advancing pushing mechanism and said massage elements and using the relative distance change of said massage elements when the back of chair massage device reaches shoulder and breech big coxal bone of users' along the massage part to enhancing the functions of massage chairs.