Co-silica nanotubes were prepared with nanofibers of [Co(NH3)6](HCO3)(CO3)·2H2O as templates. The yield and morphology of Co-silica nanotubes were influenced by the pH value of the ammonia solution, the concentration of the Co salt solution as well as the rate of ethanol addition. The optimized sample contains 100% nanotubes with 150 – 300 nm in diameter and up to 30 -m in length.