Introduction: In July 1983 the Prognoz 9 satellite was launched with the fifth Czechoslovak solar X-ray photometer of the Prognoz type (RF - 2P) onboard. This publication represents a brief description of the instrument ad survey plots of obtained data. Similar plots have been published in the three previous books containing data from the Prognoz 5, 6, 7 and 8 experiments. The Prognoz 8 satellite was launched on July 1, 1983 into the orbit of apogee of 720 000 km and perigee of 380 km, inclination of 65° and orbital period of about 641 hours. This photometer was in operation till January 15, 1984. and Kontakt: František Fárník