A soluble chemically reduced graphene oxide (RGO)/carboxymethyl cellulose (CMC) assembly was formed using a noncovalent approach. Assembly of a field-effect transistor of RGO/CMC (1:100) demonstrated that RGO plates have intrinsically hole-doped and ambipolar field-effect characteristics. It is thought that both dispersion and percolation of RGO plates in the CMC matrix are very effective in this noncovalent approach, which is promising for low-cost electronics, because of the simple preparation procedure.