Abstract: Microbial degradation of feather favors the environment protection as well as waste utilization. So, it has remarkable economic and social benefits. A highly efficient feather degrading strain (designated as Gxun-20) was isolated from the sludge of duck breeding base in Qinzhou port of Guangxi. The species information was identified using combined methods of morphological observation, physiological and biochemical characteristics and 16S rRNA gene sequence analysis. The keratinase producing conditions and enzymatic properties were also studied. The strain was identified as Brevibacillus parabrevis Gxun-20 and its optimal conditions for keratinase production were determined at temperature 34 ℃, initial medium pH 6.5, feather content 1.5%. The keratinase activity could reach 277.45 U/mL with 48 h fermentation. The maximal keratinase activity was detected at 50 ℃, pH 7.5. It showed that Ca2+ and Na+ enhanced the enzyme activity significantly, while Fe³⁺,Cu²⁺,Co²⁺,Fe²⁺and Mn²⁺ inhibited the activity. The enzyme activity was also inhibited by ethylene diaminetetra acetic acid and phenyl methyl sulfonyl fluoride, indicating that it is a serine-metallo keratinase. The enzyme remained stable with surfactants, including isopropyl alcohol, sodium dodecyl sulfate and Tween-40, of which isopropyl alcohol significantly improved the activity up to 129.34%. The substrate specificity results showed that the keratinase exhibited high activity toward β-keratin, feather and casein, but little degradation on type I collagen, α-keratin and hair. The B. parabrevis Gxun-20 strain and its keratinases have potential application for waste feather degradation.