To provide a projection display picture system for allowing an enjoying person to perform an intuitive interactive video operation at his enjoying seat as to a powerful and absorbing large-sized video without damaging the sense of absorption or reality.

This interactive projection display picture system is constituted of plural light emitting sources 12 set at the arbitrary positions of a space in which a projection picture is displayed and enjoyed for emitting light beams in invisible areas to the direction of an enjoying person so that which light emitting source emits the respective light beams can be identified, a direction instructing device 30 for receiving the light from the light emitting source, and for detecting which area part of a projection display picture on a screen is selected by the enjoying person from the received light quantity, and a projecting device for changing the projection display picture by enjoying the area part selected by an arithmetic unit 60 based on signal information from the direction indicator, or executing the related function.