Development of grassland management models has been going on for these ten years. It started at Colorado University in the 1970s. In Japan similar studies started a little later. In the present report, the following eight models for grassland management, developed mainly at NGRI, and some examples of application to estimate grassland productivity are presented :
　(1) Three 'energy flow or dry matter budget models' by Okubo et al. (1977), by Shiyomi et al. (1982) and by Okubo and Jacquard (1985).
　(2) 'A nitrogen flow model' by Shiyomi et al. (1988).
　(3) 'A simple structure model' for forecasting grassland productivity by Shiyomi et al. (1985).
　(4) Two 'grassland community models' for forecasting vegetation changes with time by Koyama et al. (1986) and some ideas by Shiyomi.
　(5) 'A model for predicting herbage biomass available to cattle' by Shiyomi, and
　(6) Relationships between meteorological pattern and grassland production.
　If we can obtain real-time information concerning weather and herbage biomass from monitor stations set up in a given large area, we can predict the grassland situation and supply these prediction to farmers from time to time just like weather forecast.