Itch is an unpleasant sensory, that produces a desire to scratch. Comparable to pain, itch is a warning system against potential threats to the host. However, chronic itch is pathological feature, which has a dramatic impact on the life quality of the patient. At present, two pathways of itch have been discovered: one is histamine-dependent pathway, another is histamine-independent pathway. In these itch pathways, different transmitters and receptors play very important roles, such as histamine, cowhage and chloroquine. In many of hypothesis about the mechanism of itch formation, the selective hypothesis and the specificity hypothesis have major impacts. This review summarizes the research progress of itch signal pathways and related receptors in recent years.