Abstract: Experimental setup was designed to distinguish photoelectric effect, thermoelectric effect and Compton effect in X rays and metal interaction. Measurements of currents in metals irradiated by obliquely incident X rays produced by X pinch show that photoelectric effect will dominate the interaction process when the X ray intensity is lower than 105 W/cm2, and thermoelectric effect will dominate when the intensity is higher. Electrons irradiated by weak X rays show individual behavior, while they show weak correlated collective behavior with increasing intensity. Thus it is reasonable to predict that macroscopic charge density modulation will appear on metal surface irradiated by ultra-intense X rays, and directed electromagnetic pulses will be produced during the de-excitation of such state