A knowledge based modeling support system is issued in this paper.Its knowledge consists of three parts:modeling rule knowledge,variable type knowledge and data mapping knowledge.The modeling rule knowledge represents the decision maker's modeling process.The variable type knowledge defines data types for all variables in the modling rule knowledge.The data mapping knowledge defines sources of the data required during solving.After the decision maker inputs a problem,the modeling support system will solve it according to the modeling knowledge automatically and at last commit the result to the decision—maker．M eanwhile，machine learning is adopted to acquire knowledge during problem solving，