Based on the results of studing a lot of rock samples by radioactive trace- experiments, a rapid method for sample preparation in Rb-Sr dating has been suggested. A new type of ion exchange column called "double bed type" has been designed. In this column AG 50W × 8 (200-400 mesh) ion exchange resin has not only been used but also an inorganic ion exchanger-ZrP (prepared in our laboratory), the former for seperating Rb and Sr from the main elements in rock and mineral, the latter for removing a trace Rb in Sr isotopic samples. For raising the efficiency of Rb-Sr separation, the techniques of burning organic. carbon at high temperature and extracting Rb and Sr from the salt and oxide by H2O have been taken, too. In such a way, the separation of Rb and Sr can be completed rapidly. It takes about 8 hours to finish the whole procedure. Only in the whole tun is 38. ml the total volume of acid elution. According to the results ofv analysing a standard K-feldspar NBS 70a; 45 samples of"granite, metamorphic and sedi- mentary rocks and ten minerals, it has been fonad that the method may be applied successfully to many kinds of rock and mineral.