PURPOSE: To provide a three-dimensional graphic display device which can simultaneously execute plane coordinate input for designating the four point plane coordinate of a quadrangle after conversion and space coordinate input for designating a space coordinate as the designating method of a perspective conversion parameter.

CONSTITUTION: This device is provided with a graphic data storage means 101, a plane coordinate input means 102 outputting the four-point plane coordinate 121, a space coordinate alteration means 103 outputting space coordinate alteration information 122 by the alteration of a viewpoint coordinate in perspective conversion, a space coordinate storage means 105 inputting space coordinate alteration information 122 and storing a four-point space coordinate, a four point designation perspective conversion parameter calculation means 104 calculating the conversion parameter by the four-point plane coordinate 121 and the four-point space coordinate 124 and outputting a four-point space coordinate 123 to the space coordinate storage means 105, a rotary perspective conversion means 106 which rotary perspective-converts graphic data 120 based on conversion parameters 135 and 136, a display device 107 displaying rotary perspective conversion data 126.