1. This experiment was carried cut to study the various nutrients effect of the cutting time on the digestibility of Arundinella hirta Tanaka. The experimental natural grass hay was dried by sunshine. The experimental animals were the 15 male New Zealand White rabbits. 2. Digestibility of nutrients was depressed as the stage of growth progresses. 3. The digestibility of crude fiber and crude protein was influenced very much (p$lt;0.01) by cutting time and the digestibility of N.F.E. and energy was influenced slightly, but there was no significant difference.