Hydrodesulphurisation is an important part of the hydrotreating process.More stringent regulations on the quality of fuels bring new requirements to the catalytic processes.The removal of sulphur has become a key issue in the oil refining and this work aims to address several aspects of the process.　　Current hydrotreatment catalysts are unable to effectively remove theses impurities in sufficient quantities to meet government regulation.The goal of this research is to develop more effective hydrotreatment catalysts for producing ultra clean fuels,possibly zero.　　In this thesis, has a brief introduction about the catalyst, the description of chemicals used and a brief description of the preparation methods used for the synthesis of catalysts are given as well as techniques used for catalyst characterization.It also describes the devices used and procedure for the HDS reaction and conditions of experiments.NiMo, RuNiMo, LaNiMo and CeNiMo supported on γ-Al2O3.The focus is on desulfurization of Ts, which is considered as most important refractory S-compounds to be desulfurized.　　The results of catalyst characterization are described and information about the structure and physicochemical properties of the prepared catalysts are described by different techniques such as thermogravimetric analysis (TGA), BET surface area,Powder X-ray diffraction, SEM, and EDX.　　Catalytic activity of Ts was investigated in continuous flow gas phase fixed bed reactor filled with 1.0g of catalyst at variable temperatures of 250℃, 300℃ and 350℃under atmospheric pressure, In order to compare the performance of the following catalysts RuNiMo/γ-Al2O3, LaNiMo/γ-Al2O3 and CeNiMo/γ-Al2O3 with the traditional NiMo/γ-Al2O3.　　Based on the results, it was found that the catalytic activity of all catalysts increases as the temperature increases with the time on stream.RuNiMo/γ-Al2O3 in the hydrodesulphurization of Ts is the best catalyst with highest conversion of Ts.Its activity increases with time on stream and temperature of the reaction.Similar trend was obtained over the other catalysts.