The research Improve efficiency of purchase to appropriate the storage by Forecast Moving Average Method Case study Big beauty shop. The objective of the study is analysis in inventory more than quantity by Cause and Effect diagram. Found that Big beauty shop dose not forecast purchase in advance. None inventory control and manage product is grouping and warehouse staff not knowledge in planning and purchase Also having made purchasing in never quantity effect inventory to more than quantity and none record inventory information having made cannot quantity inventory data in warehouse effect has high rental cost for storage and some goods has expire cannot place for sale. Researcher analysis of the data and use the theory of forecasting to purchase quantity the proper reduce inventory by forecasting method. The operation of researcher study data about best sales of Big beauty shop and apply previous sale data the calculator the quantity purchase in advance by Forecast Moving Average Method. Found difference of actual sales and Sales of forecasting from forecast in January February March April May June There is expected to move away from zero which forecast the expected move less is very reliable. From the sales forecasting products in April May June inventory quantities are likely to decrease as follows in April, inventories decreased 72% to 396 pieces, May inventories decreased 75% to 360 pieces, June inventories decreased 86% to 169 pieces. From such quantity found that the reduction of inventory of more than 50% from the quantity of products in 2014