Inventory should always be found almost in every walks of life, like in a household or within a company. In the household, inventory is held for fulfilling its needs, while in the company, inventory is held for a large amount of pupose. Thai is : (1) custober service, (2) Protect againts supply errors, (3) protect of core technology, (4) decouple succesive stages in operation. For Achieving the purpose, a firm must decide on how much to order and when an inventory is required. Adequate inventories facilitate operation activities and held assure cutomers of good service. on the other hand, carrying inventories ties up working capital on goods that sit idle. So that a function of costs and forecast or requirements is a problem to solve. There are many items of inventory, but for accounting purpose, firms classify it in three categories as (1) raw materials, (2) work-in-process, or (3) finished goods. As one of the elements or working capital, inventory is an unique item, because of its variance from time to time, inventory also need the space for protecting it. Sometimes the space needed is greater than the space for production processes. So, there are many costs to pay for holding an inventory as long as activity chain pay for holding an inventory as long as activity chain from ordering it to supplier until shipping it to the customer. In that condition, in fact, those activitites do not create value added. Expert have been trying to develop some models to manage inventory for reducing the costs, that is EOQ,P order system, Q order System, pareto system, MRP and jus in time. The last model gives raise to a question: "why inventory should exist?". Could inventory eliminated? Answering those question that is, inventory should exit because the company depends on many factor especially distance and quality. all The factors come from outside that's always fluctuate. If company has the ability to make shorter of distance between supllier and the company, as well as to increase quality to zero defect, inventory could be reduced. This research is aimed at knowing how the firms of synthetic fiber industry manage their inventories. Does the industry use one of the models of inventory management?