Astrocyte has emerged as an active regulator of brain function, which connects between blood vessels and neurons as well as is a structural component of the blood-brain barrier, From its structural characteristics, astrocyte seems to sensitively respond to oxygen tension, and, in turn, generate diverse cellular cascades. Therefore, to reveal astrocytlc events by oxygen change, we screened genes whose expressions are upregulated under reoxygenation after hypoxic stress using cDNA representational difference analysis (RDA) technique. Meteorin that regulates glial differentiation was isolated from primary cultured rat astrocytes as a hypoxia/reoxygenation regulatory factor. We cloned rat version of Meteorin (rMe-teorin) and determined full-size sequences of rMeteorin. In addition, RT-PCR analysis revealed that Meteorin was increased under reoxygenation in astrocytes and highly expressed in the developing brain. Collectively, these results suggest that Meteorin may regulate astrocyte-mediated effects in response to the change of oxygen tension in the pathophysiological states.