The multiwalled carbon nanotubes (MWNTs) are synthesized by a chemical vapor deposition and an arc discharge, and their configurations are shown by the scanning electron microscope(SEM) graph. The optical properties of the samples were measured by using of Raman spectra, the absorption spectra and fluorescence spectra. The SEM graph shows that the carbon nanotube synthesized by a chemical vapor deposition has less impurities and defects and greater diameter. The absorption spectra confirm that absorption peaks of the two samples are both at 250 nm. The photoluminescence (PL) spectra observed experimentally are variable under different excitation wavelengths. When the wavelength of the excitation light is at 248 nm, an emission band at about 480 nm is observed in the PL spectra to the samples synthesized in the two ways mentioned above and more intensive by the former one; but when the excitations at 550 nm are used the peak located at 820 nm appears only for the sample synthesized by a chemical vapor deposition.