Abstract: Mo-Ni-P impregnating solution was prepared by using basic nickel carbonate，molybdenum trioxide and phosphoric acid as raw materials.EDTA，CA and EDTA-CA were added to the impregnating solution to prepare hydrogenation catalysts that containing single complexing agent and double complexing agent.The catalysts were characterized by XRD，HRTEM，H2-TPR and NH3-TPD.It was found that the catalysts containing double complexing agents significantly reduced the interaction force between the active metals and the support compared with the single complexing agent catalysts，which was conducive to the formation of more ClassⅡ active phase， and the length of the platelet was longer，the number of platelets was more.At the same time，it could keep a larger specific surface area and pore volume，and the acid amount and medium-strong acid were also increased.Therefore，the EDTA-CA catalyst has higher HDS and HDN activity.

Key words: hydrofining；EDTA；CA；complex impregnation；hydrotreating atalysts