Abstract: The influence of process parameters on hydrogenation saturation of aromatics in FCC light cycle oil over Ni-Mo-W /γ-Al2O3 catalyst was investigated. The results show that different process conditions have different effects on the reaction of polyaromatics into mono-aromatics and then further into saturates. Under the conditions of 330 ℃, hydrogen partial pressure of 6.4 MPa, LHSV of 1.2 h-1 and H2/oil(volume ratio) of 800, polyaromatics saturation rate can reach 80.1%, the total aromatics saturation rate is 16.4% and mono-aromatics yield is 42.6%. Under the reaction conditions and the catalyst used, the maximum yield of mono-aromatics at high polyaromatics saturation rate can be realized.