Abstract: The sorbent activity index and potential activity index were presented and defined, used to evaluate the activity of S-Zorb sorbent. These indexes were organic combination of the phase content of sorbent, operation parameter and sulfur contents of both raw oil and product. Based on the industrial data, a correlation model was established which combined indexes with desulfurization ability of unit. The correlation model can evaluate whether the activity of sorbent meets the special requirement of desulphurization. Conversely，the reasonable sorbent activity index can also be deduced according to the requirement of desulphurization. Furthermore, these indexes can be used to calculate the replacing amount of fresh sorbent needed and to guide the regeneration operation. The correlation model is successfully applied in a 900 kt/a S-Zorb industrial unit of Jinan Company, SINOPEC.