Abstract: A Fe-Cu-K-Si catalyst for Fischer-Tropsch synthesis was prepared,and the effect of high temperature on the catalyst performance in slurry phase was investigated.Compared with the effect at 265 ℃,the results indicate that the slurry phase level decreases by 22%but keeps stable at 320 ℃.CO conversion rate is increased by 20%,but the selection of CO_2 is lower by 2%.In the meantime,CH_4 and C_2-C_4 hydrocarbon selection are improved respectively by 4.7% and 11.72%,C_2-C_4olefin-alkyl ratio is 1.99 higher,likewise,the C_3 and C_2hydrocarbon olefin-alkyl ratio are 3.37 and 0.87 higher respectively.The experimental data indicates that when the reaction temperature is raised to 320 ℃,the selectivity of C_(5+)hydrocarbons is decreased apparently,even though CO conversion rate,C_1-C_4 hydrocarbon selection and olefin-alkyl ratio are increased obviously.Therefore,the reaction temperature should be controlled depending on the actual needs of hydrocarbon products distribution in industrial production.