This invention relates to a body height and weight measuring machine, which operates by means of a winding transmission cord means to drive a sliding plate having sensing, measuring, and digital display functions. When the sliding plate moving upwards, the sensing means will receive the refracted infrared rays as a result of a person's height to cause said winding transmission cord means to stop moving; then, a correct height and weight will be displayed thru digital display means. The aforesaid height measurement and its digital display are done by means of a photocell sensing means being coupled to a scale plate that includes a black and transparent strip in alternate arrangement and equal width so as to have said photocell sensing means generating a forward or reverse sequence sensing signal during the sliding plate moving; then, said signals will be shown on a display means driven with driving circuit.