Novel silicon nanotubes with inner-diameter of 60-80 nm was prepared using hydrogen-added dechlorination of SiCl4 followed by chemical vapor deposition (CVD) on a NixMgyO catalyst. The TEM observation showed that the suitable reaction temperature is 973 K for the formation of silicon nanotubes. Most of silicon nanotubes have one open end and some have two closed ends. The shape of nanoscale silicon, however, is a micro-crystal type at 873 K, a rod or needle type at 993 K and an onion-type at 1023 K, respectively. Novel silicon nanotubes with inner-diameter of 60-80 nm was prepared using hydrogen-added dechlorination of SiCl4 followed by chemical vapor deposition (CVD) on a NixMgyO catalyst. The TEM observation showed that the suitable reaction temperature is 973 K for the formation of Most of the silicon nanotubes have one open end and some have two closed ends. The shape of nanoscale silicon, however, is a micro-crystal type at 873 K, a rod or needle type at 993 K and an onion-type at 1023 K, respectively.