Among the five senses, taste and olfaction play crucial roles in the detection of chemical substances in the environment and are referred to as chemical senses. In the past decade, much progress has been made in studies on molecular mechanisms of the gustatory system by methods such as those based on molecular and cellular biology, genetics, and bioinformatics. This review covers recent studies on taste receptors, intracellular signaling transduction in taste receptor cells, and taste coding at the periphery in vertebrates from fish to mammals.