Silicon-based materials are an emerging anode technology for the use in the next generation electrochemical enegy storage, because it is cheap, widely distributed on our planet and non-toxic to the environment . However, the development of commercial silicon-based anode progresses slowly due to the properties inherent to pure silicon, such as safety and capacity limiting volume expansions during cycling and poor conductive nature . Functionalization of the nanostructured silicon oxide with conductive carbon coating is one of the possible strategies to overcome these problems. Moreover, oxide matrix of silicon benefits to alleviate large volume changes [3-4]. The present work is aimed to develop a novel simple preparation technique of SiOx/C nanocomposite through mechanochemically activated sol-gel process combined with dry-ball milling (DBM) process. In this synthesis, tetraethyl orthosilicate (TEOS), aqueous ammonia and acetylene black(AB) were mixed by a high-energy ball milling at 800 rpm for 4 hours. The resulting slurry was dried at 110 oC for 2 hour in an air oven and then annealed at 600 oC for 2 hours in N2 atmosphere. The obtained sample could be identified as amorphous SiOx/C composite by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) analysis. It could be also seen a field emission scanning electron microscopy (FE-SEM) observation that the SiOx/C composite was composed of large agglomerated micro-sized particles. In order to reduce the particle size, the composite was mechanically milled at 800 rpm for 4 hours by high-energy DBM with additional AB as an additive. The as-milled sample was the SiOx/C nanocomposite consisting of highly dispersed carbon nanoparticles on fine amorphous SiOx particles. Electrochemical properties of the SiOx/C nanocomposite were evaluated by assembling a CR2032 coin-type cell. The galvanostatic charge-discharge test was performed on multichannel battery testers (Hokuto Denko,HJ1010mSM8A) between 0.01 and 3.0 V versus Li/Li+ at a current density of 50 mA g-1. The cell exhibited a highly stable reversible capacity of 620 mAh g-1 at a current density of 50 mA g-1 after 30 cycles with no capacity fading. The SiOx/C nanocomposite was also annealed at different temperatures for in 3%H2+N2 atmosphere and then evaluated its battery performance. References 1) Chang et.al., Enengy Environ. Sci, 5(2012)6895. 2) Yao et al., J. Power Sources, 196(2011)10240. 3) Yan et. al., Sci. Rep. (2013)1568. 4) Guo et al., Electrochim. Acta, 74(2012)271.