The fMRI study on the imaginary cold stimuli and real cold stimuli are reported. The similarity and difference of the brain's functional activities for the two situations have been found. Both imaginary cold stimuli and real cold stimuli are found to have excited the area SI, SII, left middle frontal gyrus and motor area of cerebrum. In addition, the imaginary cold stimuli can also excite the left interior frontal gyrus and cingulat gyrus which are not excited by real cold stimuli. However the real stimuli can also excite the right middle frontal gyrus.