Single crystals of the Cdin2S4 compound belong to the class of wide-band-gap semiconductors [ 1] with a high specific resistance on the level of p ~ 107 Ohm-cm. The band gap of Cdin2S4 thiospinel is indirect, and values between 2.1 and 2.4 eV (between 2.5 and 2.7 eV for direct gap) have been repo1ied by different authors [2]. Cdin2S4 is a high-photosensitive semiconductor in the visible range of spectnun and may be used as active material for creation of solar cells and various optoelectronic devices. The rather large values of the effective atomic number and the energy gap make Cdln2S4 a suitable material for the fabrication of X-ray detectors, which do not require being cooled. Earlier, we reported the X-ray dosimetric properties of Cdln2S4 single c1ystals doped by Cu and Fe [3,4]. It was found that the characteristic X-ray conductivity of Cdin2S4<Cu> and Cdin2S4<Fe> crystals increased compared with undoped Cdin2S4. The aim of this work was to study the effect of doping Cdin2S4 single c1ystals by gold on their X­ray dosimetric characteristics. Therefore, the fabrication of Cdin2S4<Au> c1ystals and the experimental studies of their X-ray conductivity at room temperature became our priority direction. It is found that the X-ray sensitivity coefficients of Cdin2S4<Au> crystals (with 3 mol % Au) increase 6-8 times compared with undoped Cdin2S4 at effective radiation hardness Va= 25-50 keV and dose rate E = 0.75-78.05 R/min (Table). Moreover, the persistence of the c1ystal characteristics completely disappears and the supple voltage of a Cdin2S4<Au> roentgendetector decreases threefold.