SWNTs were synthesized by laser vaporized CCVD (Catalytic Chemical Vapor Deposition). The diameter distribution and the purity of SWNTs synthesized at different temperatures, laser intensities and catalysts were investigated by Raman spectroscopy. Both of them tended to shift towards a larger area as reacting temperature or laser intensity was increased. Ni, Co and Fe played a catalytic role, though Ag and Cu were less effective at our experimental conditions. In addition, the conventional laser oven technique and laser vaporized CCVD technique were also compared. The diameter distribution of SWNTs which were synthesized by the conventional laser oven technique was narrower than that of SWNTs synthesized by the laser vaporized CCVD technique.