A yeast strain Gb identified as Debaryomyces sp.was isolated from sludge of a chemical plant by acclimatization.This strain was capable of growing in media with 20% Na₂SO₄ and utilizing phenol as sole carbon and energy sources.Effects of environmental factors on growth of this strain and degradation of phenol were tested.It was found that the optimal condition for growth and phenol degradation of this strain was phenol 1 000 mg L^-1,Na₂SO₄ 5%,pH 5.5 and temperature 30.The optimal volume is 100 ml in a 250 ml conic flask.This strain can degrade 95% phenol in 3 days when Na₂SO₄ was 5% and phe nol was 1 000 mg L^-1.The osmoregulation mechanism of this strain was studied.It was found that the intracellular level of tre halose increased with the increase of salinity,indicating that Debaryomyces sp.can use trehalose as osmoprotectant in hyper saline environment.The physiological characteristics of the strain were also studied,yielding some basic parameters useful for biodegrading of high salt concentration phenol wastewater.