Abstract: The 1 500 h experiment of catalyst stability was conducted with residue of paraffin-base Qinghai crude oil (Qinghai residue) and residue of intermediate-base Saudi Arabia light crude oil (Saudi Arabia residue) as feedstock,respectively. The differences of the molecular structures of the feedstock and products were analyzed by Fourier transform ion cyclotron resonance mass spectrometer and NMR techniques，as well as the coke- composition of post-reaction catalyst in experiment （used catalyst）. According to the results in this study，Qinghai residue has high content of saturated hydrocarbon and long numerous side-chains on aromatic rings. The accessibility of Qinghai residue can be improved by cracking its side-chains with rapidly–rising temperature at the start of run. Besides，the tendency of coking is declined. The molecular of Saudi Arabia residue has high content of aromatics with short side-chains. It can achieve high removal rate of impurity at low temperature, but it tends to form coking-precursor when the temperature is high，which is one of the main factors causing deactivation of catalyst rapidly. Saudi Arabia residue has lager amount of coke-composition of used catalyst and high proportion of hard coke compared to Qinghai residue. The reaction temperature distribution of Qinghai residue hydrogenation was optimized. The temperature of the demetallization catalyst bed was increased rapidly，while the temperature of the desulfurization catalyst bed was decreased，forming the distribution of the high temperature down to low temperature. The data showed that the hydrogenated products with the optimized temperature had better properties.

Key words: residue hydotreating, reaction performance, deactivation, molecular structure