Abstract: The recent progress in the preparation of silicon nanowires is reviewed，including the methods of laser ablation，chemical vapor deposition (CVD)，thermal evaporation，solution-growth，electrochemical technique and direct growth on silicon substrate. Advantages and disadvantages of these different methods in controlled preparation of silicon nanowires are discussed. A comprehensive review is given on the latest progress in the applications of silicon nanowires for sensors，optoelectronic devices and lithium ion battery. Finally，the existing problems and the research development trends are discussed.