Li0.3La2/3-x　AlxTi0.7-x　SixP0.3O3.3　fast　ionic　conductor　was　synthesized　by　high　temperature　solid　state　reaction.　AC　impedance　measurements　show　that　the　compositions　of　system　have　better　conductivities　in　low　doping　content　of　kaolinite,　but　the　conductivity　goes　down　from　9.0　×　10-5　S/cm　to　9.73　×　l0-6　S/cm　with　increasing　the　content　of　kaolinite.　The　activation　energy　is　about　20　kJ/mol　in　the　temperature　range　of　25-400°C.　X-ray　powder　diffraction　shows　that　the　doping　kaolinite　would　not　affect　the　structure　of　compositions　in　the　system.　The　main　phase　is　Li3xLa2/3-xTiO3　perovskite　solid　solution,　LaPO4　as　a　second　phase　also　can　be　found.　With　increasing　the　content　of　kaolinite　(x>0.04),　an　unsure　phase　appears.　IR　measurement　indicates　that　the　structure　disorder　of　PO43-　in　the　system　would　be　suppressed　by　kaolinite　doping.