Effects of nitrogen and cutting time on the fertilizer nitrogen yield of three orchardgrass varieties were studied from the view point of uptake of additional fertilizer nitrogen after the cutting, contribution of soil and fertilizer nitrogen in stubble and root (Sb + R) to the regrowth and uptake of enhanced soil nitrogen by N fertilization used labelled ammonium sulfate. The results obtained can be summarized as follows; 1. Nitrogen application at early spring was affected to accumulating the fertilizer nitrogen (FN) in Sb + Rp arts. 2. Fertilizer nitrogen distribution ratio to leaf blade + leaf sheaths and stem (Lb + LS) in C-2, it were 86.3%, 92,0% and 79.7% in Chinook, Kitamidori and S143, respectively. 3. Fertilizer nitrogen distribution ratio to Lb + LS in C-3, it were 73.9%, 70.5% and 79.6% in Chinook, Kitamidori and S143, respectively. Kitamidori variety showed a high distribution ratio to Sb + R in C-3, it was about 30% of the fertilizer nitrogen yield. 4. The Chinook and S143 showed a high relative fertilizer nitrogen yield in C-2 and Kitamidori in C-3, respectively. 5. Uptake of FN by additional fertilization after the cutting, there were about 85% of the FN in regrowth parts of three varieties in C-2, and 55% and 84% for Chinook and S143, and Kitamidori in C-3. 6. Relationship between the FN of plant and uptake of enhanced soil nitrogen showed highly significant correlation coefficient (r=0.9734, p$lt;0.001). 7. Increasing rate of soil nitrogen by the additions of nitrogen fertilizer were 44.8%, 69.7% and 42.8% in Chinook, Kitamidori and S143, respectively. The variety with high dry matter distribution ratio to root was absorbed more soil nitrogen than those of varieties with low dry matter distribution to root. 8. Relationship between the accumulated FN and SN in Sb + R, and the regrowth yield of Lb + LS after the cutting were different cuttings and varieties. Thus, the FN in Sb + R contributed to the regrowth yield of Lb+ LS more than the soil nitrogen in C-2, but the SN in Sb + R tended to increasing the contribution ratio in C-3. The SN in Sb + R of Kitamidori showed a high contribution, ratio to the regrowth yield of Lb + LS.