Abstract: In view of the existing problems for the Sichuan clay rare earth ore, such as low content of rare earth elements, high content of Al and Ca and difficult in leaching of Sc, a process consisting of alkaline decomposition - hydrochloric acid leaching was adopted in the experiment. The effect of initial acid concentration, liquid to solid ratio, leaching temperature and leaching time on the leaching of Sc was explored. The results show that leaching at a temperature of 90 ℃ for 60 min with an initial hydrochloric acid concentration of 9 mol/L and liquid to solid ratio of 2 : 1 resulted in an average leaching rate of Sc reaching 94%, the total leaching rate of Al, Ca, Fe, Mg and Ti were 45%, 98%, 68% and 71% respectively. This process can realize the leaching, extraction and utilization of Sichuan clay type rare earth ore.