The Central and Eastern European Countries Agricultural Simulation Model (CEEC-ASIM) has been developed at IAMO. It is a partial equilibrium model for the agricultural sectors of 14 countries including demand of domestic consumers and is designed to analyse the impacts of agricultural policies on important target variables like producer and consumer prices, supply and input demand of agriculture, food demand, net trade and welfare. Particular efforts were undertaken to implement also the policy instruments of the Common Agricultural Policy of the European Union. These besides the market price support measures also include the different forms of domestic support as for example area payments and beef premiums. Also the set-aside obligations and production quotas can be taken into account. This discussion paper serves as a model documentation and describes the structure of the model along with the basic modelling assumptions. The model is essentially based on neoclassical theory. The main hypotheses are perfect markets, profit maximisation of producers and utility maximisation of consumers.