This paper studied the absorption and desorption characteristics of cyclohexane and benzene on the low Ni/Al₂O₃ catalyst by the method of TPD, and the dispersion-degree of Ni on the low Ni/Al₂O₃ Catalyst was determined, The result indicated that there were at least two kinds of adsorption centre on the surface of the catalyst, The dispersion degree of Ni was improved, Benzene and cyclohexane were the first order reversible adsorption and desorption process. The energetic distribution of the catalyst is unequal.