The carotid body is a peripheral chemoreceptor located in the branches of the internal and external carotid arteries, and has long been known to be involved in oxygen sensing. However, the precise molecular mechanism of oxygen sensing remains unclear. Our group has previously identified that TRPA1, a type of non selective cation channel, is activated in hypoxic conditions. To understand whether TRPA1 contributes to oxygen sensing in the carotid body, we have performed immunohistochemistry experiments, which revealed that TRPA1 is expressed in the carotid body. Furthermore, Ca²⁺ imaging experiments suggested that TRPA1 in the carotid body did not contribute to the response to severe hypoxia, but the respond to moderate hypoxia. Taken together, our results suggest that TRPA1 may play a role in the oxygen sensing mechanism in the carotid body.