PURPOSE: To provide automating technique for a (caddyless) golf course so as to play golf without a caddy.

CONSTITUTION: According to the position detecting method, as dimples in the surface of a golf ball 1 are concave, concave reflecting plates are formed on the plural dimples by a bright metal film and transparent resin to make strong reflected light 7 produced by converging the sun light reach a long distance and prevent the sunlight from dazzling player's eyes in the case of handling the golf ball at close range, and the individual balls are discriminated by varying their colors. These reflected light beams 7 are detected by a television camera 8 and the falling positions of the respective golf balls 1 are composed on a course previously input to a display 10 to automatically detect the falling positions of golf balls and display the same.