In order to study the photoresponse of large area multi-walled carbon nanotubes(MWNTs),the large area multi-walled carbon nanotube films are obtained by stripping technique and spi n coating.A laser with wavelength of 532nm is used as irradiating light source.The photocurrent/volt age under the condition of different laser spot locations is observed.The experimental results indicate that the p hotocurrent/voltage is related to the laser illumination location.A maximum photocurrent/voltage occurs when la ser illumination is far away from the geometric center (contact regions of metal electrode and CNT films ),and the photocurrents of the two sides are 0.04μA and －0.06μA,the photovoltages are 0.04m V and －0.06mV,respectively.A value of nearly zero occurs when laser illuminates the geometric center of the films.Theoretical analysis suggests that the photo-thermo-electric effect is the main contributi on to the photocurrent/voltage.