As a new kind of carbon nanostructured material, graphene and its derivatives have attracted extensive attention owing to their outstanding optical limiting (OL) properties. However, most of the current studies concentrate on liquid matrix. In this work, we use chitosan (CS) as matrix and homogeneously disperse graphene oxide (GO) into it to prepare GO-CS composite films. We comparatively study the different OL effects and mechanisms of GO in liquid and solid matrix. The results show that GO presents stronger nonlinear optical effect and weaker nonlinear optical scatter, which indicates that different from carbon nanotubes, GO may possess multi sort of nonlinear optical effects.