Abstract: In order to determine the proportional calorific capacity of mixed cr-ude in oil pipeline on time, tlie author puts forward a meth od for calculating the proportional calorific capacity of mixed crude Ly way of using weighted calculation on the calorific capacity data of crude sample. By comparing qua-ntitative monitoring data with calculating results, it has been proved that the calculating method in the paper has a good relation with the practical monitoring proportional calorific capacity and tempreture of mixed crude, and that the difference is less than 5%. It has been proved too by calculation and analysis that this method has an enough precision and has a practical value on engineering for preparing oil pipeline operational plan and pred-etermining oil pipeline operational program.