A silicon/carbon composite comprises mesoporous silicon particles and carbon coating provided on the silicon particles, wherein the silicon particles have two pore size distribution of 2-4 nm and 20-40 nm. A process of preparing the silicon/carbon composite comprises the steps of preparing mesoporous silicon particles via a mechanochemical reaction between SiCl4 and Li33Si4 under ball milling and subsequent thermal treatment and washing process, and coating the mesoporous silicon particles with carbon. An anode for lithium ion battery comprises the silicon/carbon composite. A lithium ion battery comprises the silicon/carbon composite.