The thermostability, structure, oxidized functional group and hydrophilic of the different reduction temperature of graphene oxide were investigated by TG-DTA, XRD, FTIR, Raman and Water contact angle analysis. There are three stages in the process. The first stage, under 150℃, desorption of adsorbed water on the graphene oxide, hydrophilic is best. The second stage, at 150–300℃, thermal decomposition of partial oxide functional group, graphene oxide was partly thermal reduction, hydrophilic diminishing. The third stage, at 300–550℃, temperature of 300–450℃ when oxidized functional group of graphene oxide is further decomposition, hydrophilic further reduced, temperature of 450–550℃, the carbon skeleton of graphene oxide decomposition. The thermal reduction process of graphene oxide only removed the oxidized functional group their structural deficiencies have not been restored, but due to thermal reduction process and build new structure defect.