The effects of operating conditions on the distribution of olefins in the FCC gasoline,obtained during catalytic cracking reaction in the presence of the GOR-Q catalyst and conventional MLC-500 catalyst,have been studied in detail.The test results showed that the GOR-Q catalyst could obviously reduce the content of several kinds of olefins in FCC gasoline. Olefins in the FCC gasoline consist mainly of C_5 - C_7 compounds,that are composed of C=C bond with normal or monobranched chains.The reduction of gasoline olefin content could be achieved by decreasing the content of above-mentioned olefins.Lower reaction temperature,lower weight hourly space velocity(WHSV) and higher catalyst to oil ratio would help to reduce the content of olefins with a C = C double bond,normal olefins,mono-branched-chain olefins and diolefins.To decrease the loss of gasoline octane number,the operation for olefin reduction should be firstly focused on increasing the catalyst to oil ratio. The effects of operating conditions on the distribution of olefins in the FCC gasoline, obtained during the catalytic cracking reaction in the presence of the GOR-Q catalyst and conventional MLC-500 catalyst, have been studied in detail. The test results showed that the GOR- Q catalysts could obviously reduce the content of several kinds of olefins in FCC gasoline. Olefins in the FCC gasoline consist mainly in C_5 - C_7 compounds, that are composed of C = C bond with normal or monobranched chains. Reduction of gasoline olefin content could be achieved by decreasing the content of above-mentioned olefins.Lower reaction temperature, lower weight hourly space velocity (WHSV) and higher catalyst to oil ratio would help to reduce the content of olefins with a C = C double bond, normal olefins, mono -branched-chain olefins and diolefins.To decrease the loss of gasoline octane number, the operation for olefin reduction should be first focused on increasing the catalyst to oil ratio.