In-situ carbon-coated tin oxide (ISCC-SnO2) was fabricated by colloidal processing and sucrose was used as a soluble carbon source. ISCC-SnO2 was characterized by X-ray diffraction (XRD), Raman spectroscopy, and nitrogen adsorption–desorption by BET methods, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) properties of ISCC-SnO2 were investigated in 1 M Na2SO4 solution. The specific capacitance of ISCC-SnO2 was achieved 42.7 mFcm−2 at a scan rate of 25 mVs−1 and showed excellent charge–discharge behavior.