Abstract: More often than not, the economic benefit gained by Chensilou Coal Preparation Plant through selling cleaned small coal is less than that for selling untreated raw small coal. For attaining an maximized economic efficiency, and in line of the specific operating conditions of the plant, a analysis is made on the variation of raw coal property as well as marketing pricess of both cleaned and uncleaned small coal products, and then the economic results that can be gained by selling the products of different structures are compared. The calculating methods for making product structure adjustment in the cases of washing both sized and unsized coal are proposed. Practice shows that once the marketing prices of coal and raw coal property fluctuate, the product structure is required to be accordingly readjusted in time according to real-time price calculation.