Local density augmentation around exciplex between anthracene and N,N-dimethylaniline in supercritical carbon dioxide was measured by fluorescence lifetime at 40 degreesC and at pressures from 9.3 to 19.1 MPa. In the near-critical (9.3-10.5 MPa) region, the exciplex was more stable than that predicted by Kirkwood analysis, which means strong influence of local density augmentation around the exciplex. (C) 2002 Published by Elsevier Science B.V.