This study was conducted at the rice field of Livestock Experiment station, Suweon to investigate the effects of harvesting time on forage production and quality of rye (Secale cereale L.) on paddies. The results obtained are summarized as follows; 1. Fresh matter yield was peaked at the 10 days (May 10) after heading, however, dry matter yield was increased in proportion to maturity. 2. Digestibility (in vitro) showed the 83-77% by heading stage (Apr. 25-30) but decreased to 66-58% after heading stage. 3. Digestible yield reached to maximum level, 619.2 kg/lOa at the 10 days after heading (May 10). 4. The content of crude protein and crude fat in forage rye was decreased with advancing the maturity. 5. The lactic acid content of rye silage ranged from 1.3% to 2.0%.