THE HYDROTREATING catalyst development is an essential ……..factor to produce clean fuels. The catalytic performance of CoMoS/CNT on Hydrotreating of the Egyptian heavy vacuum gas oil was investigated. Firstly the CNT was functionalized with concentrated HNO₃. The Mo and Co wt% were loaded on CNT by impregnation methods. The catalyst was characterized by X-ray diffraction, Raman Spectroscopy, TEM, and BET. The hydrotreating experiments were conducted on autoclave reactor at various operating conditions of Temperature (325-375) ^oC, pressure (20- 60) bar, time (2-6) h and cat/oil ratio of 1:75, 33 and 10. The result indicated that the CoMoS/CNT was an efficient for the hydrotreating process. Also, the hydride-sulfurization (HDS) enhanced with increasing catalyst/oil ratio. Moreover, Results revealed that the optimum condition (temperature 350 ^oC, Pressure 40 bar, catalyst/oil ratio of 1:75 for 2 hr, was chosen. Additionally, even at low catalyst ratio of 1:75 an acceptable HDS% of 77.1 was achieved.