Abstract: The cracking contact catalyst contaminated by different amount of calcium was studied by BET, NH3-TPD, FT-IR, SEM-EDX. The contaminated catalyst samples were evaluated in a micro-reactor and a fixed-fluidized bed reactor. The results show that both the specific surface area and the pore volume decrease because of pollution. The total acid number and micro-activity of contaminated catalysts decrease even more. However, the pore size distribution suffers no changes. The calcium from calcium naphthenate deposits evenly in the bulk phase of the contact catalysts. The calcium contamination can make Tahe AR FCC product change significantly.