Aligned carbon nanotubes (ACNTs) films are grown at low substrate temperature (500 ℃) by plasma-enhanced hot filament chemical vapor deposition (PE-HF-CVD) method. A gas mixture of methane, hydrogen and nitrogen is used as the reaction gas, with nickel particles prepared by spin coating nickel nitrate solution on silicon, heat treatment and deoxidization with H2 as catalyzer. The carbon nanotubes prepared by 1 mol/l nickel nitrate solution are well aligned shown by scanning electron microscope (SEM) and transmission electron microscope (TEM) with 30～50 nm diameter, more than 4 μm long. Raman spectrum is used to display the carbon nanotubes film samples prepared by different concentrations of nickel nitrate solution.