A typical acid hydrolysis residue (AHR) was adopted as material to make char in a tube reactor with low heating rate. Proximate analysis was carried out to show component differences between AHR and the char. The crystal structure and morphology of char samples were characterized by X-ray diffractometry (XRD) and scanning electron microscopy (SEM), and were analyzed to explain changes of CO2 gasification reactivity. The CO2 gasification reactivity of acid hydrolysis residue was studied in the view of the rate of weight loss by a thermal gravimetric analyzer. The results showed carbonization increased as pyrolysis temperature rised, increase of final pyrolysis temperature enhanced the degree of crystallike ordering, and the degree of char deconstruction increased with final pyrolysis temperature increasing. The CO2 gasification reactivity showed a decrease tendency when final pyrolysis temperature increases.