Abstract:In humans (and probably other mammals),it is generally agreed that there are five basic taste qualities: sweet, bitter, umami, salty and sour. Recent compelling evidence from rodent and human studies raise the possibility for an additional sixth taste modality devoted to the perception of lipids (fat taste). It has been shown that zebrafish can perceive amino acids, bitter tastant as taste stimulants,then what about fat taste?Until now,it has not been reported yet. Based on this, behavioral experiments were conducted to detect the existence of fat taste in Danio rerio and Pangasius sutchi. It was shown that fish can perceive not only bitter and amino acids tastants, but also fatty acids. In addition, we found that P. sutchi had a preference for sweet taste, which is inconsistent with the previous report that there was no sweet taste in zebrafish.