Abstract: At present, most of the crude oil and oil products in refineries are transported by rail tank cars, which amount to about 40 000. In practical operation, it is so slow to do the metering and easy to make mistakes because of frequent input and output, tremendous quantity of work and complicated calcultion as to lead to unaccurate metering in addition to affecting railway dispatch and reudction of turnover rate. Whether the tank volumetric metering is accurcte or not concerns a great deal with cost accounting, enterprise management and foreigh trade. To solve this problem, a computer programe similarizing manual calculation has been made out and put into production as a result of systematic research and, exploration of the manual calculation and the usual calculation table and summary of the practical operating and mctering experiences.