The aim of this study was to study the effects of fermentation and enzymatic hydrolysis treatment of cottonseed meal on crude protein (CP), water-soluble protein (WSP), amino acid (AA) and peptide fractions, and the AA digestibility and metabolic energy of fermented cottonseed meal (FCSM) and enzymatic hydrolyzed cotton seed meal (EHCSM) in white leghorn roosters. Firstly, CSM were fermented with Aspergillus niger, or hydrolyzed with alcalase and flavourzyme. Secondly, a total of 32 white leghorn roosters with similar body weight (1.95± 0.14 kg) were randomly assigned into 1 of 4 treatments, 1) starvation group, 2) untreated CSM group, 3) FCSM group, and 4) EHCSM group to determinate the Apparent metabolic energy (AME), True metabolic energy (TME) and AA digestibility. Results showed that: (1) CP content in FCSM and EHCSM increased 8.42% (P < 0.05) and 1.11% (P > 0.05), WSP content increased about 5.64 -fold (P < 0.05) and 6.39 -fold (P < 0.05), total AA content increased 8.95% and 8.95%, respectively; the peptide fractions (≤ 600 Da, 600-1800 Da and ≥1800 Da) in FCSM and EHCSM increased significantly (P < 0.05). (2) FCSM, and EHCSM has no effects on AA digestibility and AME (P > 0.05), but the TME for FCSM was significant higher than untreated CSM and EHCSM (P < 0.05). Our results suggest that the solid-state fermentation and enzymatic hydrolysis method offer effective approach to improving the quality of unconventional protein sources, such as the CSM.