delta-Integration can improve the expression stability and increase the copy number of exogenous genes in Saccharomyces cerevisiae. Generally, delta-integration vectors employ auxotrophic markers, such as LEU2-d, HIS3, TRP1, and URA3, to screen transformants. In this study, two cellulase genes (beta-glucosidase and endoglucanase) were integrated into the S. cerevisiae W303-1A chromosome as reporters, by delta-integration with the aforementioned auxotrophic markers. Eight strains, L-BGL, H-BGL, T-BGL, U-BGL, L-EG, H-EG, T-EG, and U-EG, were selected and tested. After 5 days growth, cellulase activities (U ml(-1)) were 3, 2.3, 1.8, 1.5, 29, 12, 8, and 1.5, respectively. The results showed that auxotrophic markers influenced the expression of cellulase genes.