Abstract: The commercial application of LDO-70 catalyst for residue catalytic cracking in the 1.2 Mt?a-1 RFCC unit of PetroChina Wulumqi Petrochemical Company was introduced. Compared with base case, the slurry yield decreases by 0.35%, the yield of dry gas and coke reduces by 0.50% and 0.77%, respectively. The commercial results also show that the total liquid yield increases by 1.69%, the light oil yield increases by 1.45%. Especially the additional increment of propylene of 1.1%, and 1.7 units RON of gasoline are obtained. LDO-70 catalyst can significantly increase heavy oil conversion and propylene yield and improve the product distribution and the octane number of gasoline.