A tin dioxide/reduced graphene oxide composite (SnO2/RGO) is synthesized using combined methods, including in-situ metal fin reduction, spray drying and thermal treatment. Under mild hydrothermal condition, metal fin works as both reducing agent for few-layered graphene oxide (GO) to prepare restacked 2-dimensional (2D) reduced graphene oxide (RGO) sheets and metal source for homogeneously distributed nanostructured Sn and Sn oxides (Sn/SnO/SnO2). The 2D precursors are shrunk to a micro-sized dried blueberry shape via a spray drying process. After further thermal treatment, SnO2/RGO composite is obtained, in which Sn and SnO species are converted to SnO2 and the nano-sized SnO2 is well stabilized by the micro-sized 3D porous RGO supporting framework. The 3D SnO2/RGO composite exhibits not only a higher reversible capacity of 708 mAh.g(-1) under a current density of 500 mA.g(-1) over 150 cycles compared with 2D counterpart, but also a long and stable cycling life under a high current density of 1000 mA.g(-1). This synthesis route can be considered as simple, economic and environmental-friendly, and it has great potential to find applications in other fields.