This invention relates generally to a method for growing carbon fiber from single-wall carbon nanotube (SWNT) molecular arrays. In one embodiment, the present invention involves a macroscopic molecular array of at least about 106 tubular carbon molecules in generally parallel orientation and having substantially similar lengths in the range of from about 50 to about 500 nanometers. The hemispheric fullerene cap is removed from the upper ends of the tubular carbon molecules in the array. The upper ends of the tubular carbon molecules in the array are then contacted with a catalytic metal. A gaseous source of carbon is supplied to the end of the array while localized energy is applied to the end of the array in order to heat the end to a temperature in the range of about 500null C. to about 1300null C. The growing carbon fiber is continuously recovered.