▎ 摘　　要

Graphite oxide was prepared by Hummers method, then it was obtained by ultrasound. Finally, graphene was prepared by using hydrazine hydrate as reducing agent. We can get the influences of oxidation time on the graphene structure by different reacting times. Ultrasonication can reduce the aggregation of graphene efficiently. The morphology and size of graphene were characterized by SEM, TEM, XRD and FTIR. Through this method, we can get high quality graphene which has smooth surface and fewer defects. The longer the oxidation time, the more easier it is to peel and insert functional groups.