To study the effects of harvest time on quantity and quality of corn forage, this research was conducted ot University of Zabol in 2005. Experiment carried out in randomized complete block design with four replications and three different harvest times at tassel emergence (H1), milked stage (H2) and dough stage (H3). Result of statistical analysis showed that effect of harvest time on traits like plant height, weight of leaves, stem, ear, dry matter and dry matter yield per hectare were significant. Highest plant, ear weight and dry matter achived from H3 treatment harvest at dough stage. Highest leaf weight, stem and number of leaves achieved from H1 treatment harvest at milk stage. Delayed harvest changed quality of corn forage; and resulted in increases in dry matter, fatty percentage, ADF, ADL and NDF. Highest carbohydrate content obtained in H2 treatment harvest dough stage and then decreased drastically. Concentrations of most nutrients content of the forage at different harvest times were not affected. Ash and crude protein content of forage did not change after H1 treatment. According to the results of this research, in can be concluded that harvesting the forage at mike stage increases both quality and quantity of corn forage.