Aureobasidium pullulans DSM-73015 grown on modified Biely's medium with different carbon sources at 1% concentration secreted very low levels of β-1,4-xylanase (148.4-4680.9 nkat mL-1; 675.1-9752.0 nkat/mg protein). Xylose was the best carbon source inducer upon addition of EDTA and NH4NOh simultaneously into the culture medium. In this case, both the volumetric and specific activities increased up to 4680.9 nkat mL-1 and 9752.0 nkat/mg protein. The highest volumetric ( 13080.9 nkat mL-1 ) and specific activity (14964.6 nkat/mg protein) were obtained after 96 h of cultivation on 3% xylose-containing medium supplemented with EDTA and NH4NO:ł at 0.06% and 0.6% (w/v) concentrations, respectively, at an initial pH value of 4. Added EDTA showed concentration-dependent stimulatory effect on β-l,4-xylanase synthesis and about 16.7-22 and 1.5-22-folds increase in both volumetric and specific activities were achieved compared to that obtained initially on Biely's medium at 1% xylose concentration.