In recent years, fatty acids with the characteristics of the basic taste has been reported, and the point that fatty acids are the sixth basic taste has been proposed. Based on several aspects, such as electrophysiological characteristics of organisms, psychophysics characteristics, the main taste receptors, compared with other basic taste, the significance of fat taste, this paper reports that the evidence about the fat taste as the sixth basic taste is insufficient based on the existing literatures and the argument conditions of the basic taste.