Relatively high content of nitrogen and sulfur in shale oil can have an adverse influence on its potential utilization as a substitute fuel. In this paper, the results of preliminary investigation into catalytic hydrotreating of diesel fraction (200-360 degrees C) of Fushun shale oil are presented. Hydrogenation was carried out in a fixed-bed reactor using sulfided catalysts Ni-W/Al(2)O(3) and Co-Mo/Al(2)O(3). The influence of temperature, pressure, liquid hourly space velocity (LHSV) and hydrogen/feedstock ratio on hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) was investigated. Catalytic activities of two catalysts were compared. The results showed that increasing temperature, high pressure and long residence time (reciprocal of LHSV) promoted the removal of sulfur and nitrogen, while the impact of hydrogen/feedstock ratio was smaller. The degree of nitrogen removal was substantially higher than that of sulfur. HDS efficiencies of two catalysts were comparable in severe conditions. The catalyst Ni-W/Al(2)O(3) was much more active at HDN than Co-Mo/Al(2)O(3) catalyst in all conditions selected. The oil cleaned in optimum conditions is characterized by low content of sulfur, nitrogen and alkenes. It can be used as a more valuable fuel.