Due to their high specific surface area, graphene oxide and graphene oxide-base nanoparticles have great potential both in dual-drug delivery and combination chemotherapy. Herein, we developed cisplatin (pt) and doxorubicin (DoX) dual-drug-loaded peGylated nano-graphene oxide (pGo) to facilitate combined chemotherapy in one system. In this study, nano-sized pGO-Pt/DOX ranged around 161.50 nm was fabricated and characterized using zeta-potential, AFM, TEM, Raman, UV-Vis, and FTIR analyses. The drug delivery efficacy of Pt was enhanced through the introduction of pGO, and the final weight ratio of DOX: Pt: pGO was optimized to 0.376: 0.376: 1. In vitro studies revealed that pGO-Pt/ DOX nanoparticles could be effectively delivered into tumor cells, in which they induced prominent cell apoptosis and necrosis and exhibited higher growth inhibition than the single drug delivery system or free drugs. The pGO-Pt/DOX induced the most prominent cancer cell apoptosis and necrosis rate with 18.6%, which was observed almost 2 times higher than that of pGO-Pt or pGO-DOX groups. in the apoptosis and necrotic quadrants In vivo data confirmed that the pGO-Pt/DOX dual-drug delivery system attenuated the toxicity of pt and DoX to normal organs compared to free drugs. the tumor inhibition data, histopathology observations, and immunohistochemical staining confirmed that the dual-drug delivery system presented a better anticancer effect than free drugs. These results clearly indicated that the pGO-Pt/DOX dual-drug delivery system provided the means for combination drug delivery in cancer treatment. To improve the efficacy and reduce side effects of anticancer drugs, nanoparticle drug delivery systems (DDSs) have been widely explored in the past few decades 1. Graphene, one of the most popular nanoparticles, has attracted tremendous attentions in the DDSs field due to its unique physical and chemical properties 2. Graphene is a two-dimensional single layer constituted of sp 2-hybridized carbon, which could supply a excellent drug-load ability with its high specific surface area. As a derivatives of graphene, graphene oxide (GO), which could be detected to have hydroxyl, carbonyl, carboxyl and epoxide functional groups on thesurfaces of each shee 3. The presence of those reactive functional groups imparts GO with excellent aqueous solubility, biocompatibility and multi-functionalities, which is essential for the delivery of anticancer drugs 4. Because of the unique properties of graphene oxide (GO), many efforts have been made to load anticancer drugs onto GO efficiently by either non-covalent or covalent bonds 5. For instance, Dai and colleagues 6 first attached hydrophobic aromatic molecules such as a camptothecin analogue (SN38) to the GO surface. The resulting GO-SN38 complex exhibits enhanced solubility and higher anticancer ability than the original SN38 prodrug does. In our previous study 7 , cisplatin (Pt) was carried by PEG-functionalized GO (pGO), and the as-prepared GO-Pt exhibits improved drug loading efficiency and enhance...