A pool experiment was carried out to study the effects of different nitrogen applicationstrategies (rates and stages of nitrogen application) on yield and forage nutritivequality of Zea mexicana cultivated in summer, 2002. In the whole growing stage, its stemwas clipped three times at the height of 25cm when it was 110cm high (H1, H2 and H3 standfor the first, second and third harvest stage, respectively). Six indexes includingcrude protein (CP), ether extract (EE), nitrogen free extract (NFE), acid detergentfiber (ADF), crude ash (CA), and general energy (GE) were employed to evaluate the foragenutritive value. The results showed that the content of CP and EE increased but thecontent of CA and ADF decreased under the two nitrogen rates (High-rate N, 600kgha-1;Mid-rate N, 300kgha-1). The fresh and dry harvest biomass of the whole plants on H1 andthose of the leaves on H2 were also improved. But the stalks on H2 and the whole plantson H3 were affected mainly by dressing nitrogen fertilizer. The yield of CP and EE, CA,NFE, and GE was mainly affected by nitrogen rates. The ADF yield increased was due to theincrement of the fresh and dry harvest biomass. Nitrogen applied as base fertilizer forsummer Zea mexicana can be harvested a higher biomass and improve the forage nutritivequality. A pool experiment was carried out to study the effects of different nitrogen application strategies (rates and stages of nitrogen application) on yield and forage nutritive quality of Zea mexicana cultivated in summer, 2002. In the whole growing stage, whose stemwas clipped three times at the height of 25 cm when it was 110 cm high (H1, H2 and H3 stand for the first, second and third harvest stages, respectively). Six indexes including crude protein (CP), ether extract (EE), nitrogen free extract ADF), crude ash (CA), and general energy (GE) were employed to evaluate the foragenutrient value. The results showed that content of CP and EE increased but thecontent of CA and ADF decreased under the two nitrogen rates (High-rate N, 600 kg ha-1; Mid-rate N, 300 kg ha-1). The fresh and dry harvest biomass of the whole plants on H1 and the whole of the leaves on H2 were also improved. mainly by dressing nitrogen fertili The yield of CP and EE, CA, NFE, and GE was mainly affected by nitrogen rates. The ADF yield increased was due to the increase was the fresh and dry harvest biomass. Nitrogen applied as base fertilizer forsummer Zea mexicana can be harvested a higher biomass and improve the forage nutritivequality.