Abstract:[Objective] To develop a novel and efficient amino acid fertilizer, a liquid fermentation of waste feathers was established and optimized aiming at enhancing the degradation of waste feather and yield of amino acid. [Methods] Bacillus amyloliquefaciens 3-2 was used to ferment feathers. The influences of fermentation temperature, time, feathers content, sole carbon source, carbon-nitrogen complex and metal ions on the degradation of feather as well as the kinds and yield of amino acids were studied. [results] No positive correlation between degradation of waste feathers and yield of amino acid was observed. Increase of fermentation time contributed to the degradation of feathers. The optimal fermentation conditions of degradation of feathers were 37 °C, 1% feather, lactose as external carbon source and Mg2+ and the highest degradation of feathers was 81.92%. The increase of feathers content favored the yield of amino acids (less than 20%). The optimal conditions of kinds and yield of amino acids were 37 °C, 108 h, 10% feathers, 0.5% lactose and no carbon-nitrogen complex and metal ions with the kinds of 17 and highest yield of 20.861 g/kg amino acids. [Conclusion] The production of nutrient-rich amino acids fertilizer from waste feathers by fermentation of Bacillus amyloliquefaciens 3-2 is a reliable, eco-friendly and economical technology. The results will be a technological support to develop novel amino acids fertilizer.