Abstract: In order to determine the optimal liquid medium for the secretion of laccase by Ganoderma sinense strain Gs-1 with submerged fermentation, the laccase activity of G. sinense strain Gs-1 with submerged fermentation was used as an index in this study, and single factor experiments were used to study the effects of carbon sources, nitrogen sources, metal ions, and agricultural by-products as inducers on laccase secretion by G. sinense strain Gs-1 with submerged fermentation. Then the Box-Behnken experimental design was used to optimize the liquid medium for the secretion of laccase by G. sinense strain Gs-1 with submerged fermentation. The results showed that the optimal carbon source for the secretion of laccase by G. sinense strain Gs-1 with submerged fermentation was glucose and the optimal concentration of glucose was 19.21 g/L; the optimal nitrogen source for the secretion of laccase by G. sinense strain Gs-1 with submerged fermentation was tryptone and the optimal concentration of tryptone was 2.0 g/L; the optimal metal ion for the secretion of laccase by G. sinense strain Gs-1 with submerged fermentation was Cu²⁺ and the optimal concentration of Cu²⁺ was 1.08 mmol/L; the optimal agricultural by-product for the secretion of laccase by G. sinense strain Gs-1 with submerged fermentation was soybean meal and the optimal concentration of soybean meal was 32.59 g/L. Under these optimized conditions, the activity of laccase secreted by G. sinense strain Gs-1 with submerged fermentation could reach 6 787.58 U/L, which was 26.46 times of laccase activity secreted by G. sinense strain Gs-1 with submerged fermentation in the unoptimized medium. The optimization of G. sinense strain Gs-1 liquid medium greatly improved the activity of its extracellular laccase, and the results laid a solid foundation for the industrial production of G. sinense strain laccase.