Abstract: Studies a calculation method on economic benefit of depressant transporting process. Based on the theory of oil transporting process, simulates two oil transporting plans of depressant and non depressant transportation, using real productive data in oil transporting production, and establishes a mathematics model calculating economic benefit of depressant transportation and its relative quota system. Introduces individually a mathematics model and its relative quota system on fuel oil consumption and cost, power consumed and cost, fixed assets depreciation, variable cost for depressant and non depressant transportation, and finally analyzes major factors affecting economic benefit of depressant operation.