The experiment was carried out to investigate the effect of extension of grazing duration in late autumn on grass growth in following spring, in order to improve the rate of self-sufficiency for roughage feed. Plant height, total biomass and litter production of herbage were increased when the grazing was finished early in late autumn. The proportions of clover and litter, and amounts of animal intake were decreased, with extended grazing duration in late autumn. But when the grazing was finished late in autumn, the contents of crude protein (CP, %) of herbage were increased, contents of acid detergent fiber (ADF, %), neutral detergent fiber (NDF, %) and crude ash (%) were decreased in pasture after grazing, therefore the contents of total digestible nutrients (TDN, %) and relative feed value (RFV) of herbage were improved. The early end grazing showed that plant height, total biomass and litter production of herbage in following spring were higher than those in late end grazing. However, increased yields were not significantly different among end grazing treatments (0.12-0.15 tonha), except for the final end grazing in late autumn (0.01 tonha). With extended grazing duration in late autumn, the contents of CP of herbage in following spring were increased, contents of ADF, were decreased, and RFV were improved. (Key words : Extension of grazing duration, Plant height, Biomass, Amount of intake, Increased yield, Crude protein, TDN) rll\ulcorner c# qiil x i 9 ~ 1 a% * (College of Natural Resources, Taegu Univ., Kyongsan, 71 2-714, Korea) * $4 4 qiil 34 qq(Co1lege of Liberal Arts & Sciences, Yonsei Univ., Wonju, 220-701, Korea) '* 8 * jL@%ft@ &@%(Faculty of Agriculture, Hokkaido Univ., Sapporo, 060 Japan)