Presented paper is devoted to the construction of cracking catalysts based on H-form zeolite Y, modifying by heteropolyacids of 12 row decationzed forms of natural clays of Tagan and Narynkol deposits. Conditions of acid activation were compared for Tagan clay. Chemical composition of clays before and after activation was detected by optical emission spectral method; phase composition was detected with X-ray<br />diffraction. It has been shown that activities of composite catalysts are related to the concentration and sequence of HPA adding. From the results the conclusion was drawn that amount of adding HPA influenced the activity and thermal stability of catalysts prepared on the base of Tagan and Narynkol clays deposits. The synthesized catalysts were studied in a laboratory microimpulse catalytic set by the model reaction of isopropylbenzene cracking at temperature 350-500 °C. The optimum compositions of zeolite containing contacts served as the base of creation of cracking catalysts for real raw (kerosene-gas-oil fraction) into quartz reactor with a fixed catalyst bed. These prepared catalysts have demonstrated enhanced thermal<br />stability and high activity. Stronger cracking activity of catalysts prepared on the base of Narynkol clay has been shown.