Tissue acidosis is a general phenomenon under physiological and pathological conditions. Through acid-sensing ion channels (ASICs), neuron can detect the drops in extracellular pH. ASICs are one of members of DEG/ENaC family. To date, six subunits of ASICs family have been identified. They are widely expressed in the peripheral and central nervous system. The homomers and heteromers channels of these subunits exhibit a variety of electrophysiological properties. ASICs play a critical role in several modalities of sensation, especially nociception.