Abstract: The condition of market varys obviously.How factory’s decision_making changes with the market is a urgent problem which needs to be resolved,especially in pulp and paper_making industry.This paper develops a Production Decision Support System(PDSS) served for large_scale and multiple_products factories in the process of production decision_making.The approach is integrated by using computer technology,system science,decision science and artificial intelligence.This article focuses on:(1) the decision_making process for production;(2) the objectives and the functions of the PDSS;(3) the software design of PDSS.The system is used to improve firm’s production decision, help firms adapt to market’s change and win in the competition.