A study was made on the dose rate calculation of the rotational $^{60}$Co teletherapy, employing aluminum therapy table which has no known dimensions of the table thickness. Two methods were used in order to determine the thickness of aluminum therapy table. One was by estimation of table thickness and the other was by measurements of radiation dose rates. These two results were compared and found to be in good agreement. For the radiation dose rate measurement, paraffia wax phantom and patients of carcinoma of the utrine cervix were employed. Since paraffin wax was known to be a tissue-equivalent material, the results of measurement for both objects were in goodagreement, and the measurements with phantom were justified. The calculation method of thedose rate on the $^{60}$<TEX>Co teletherapy was thoroughly explained in order to use for the calculation of the axis dose rate with and without aluminum therapy table. T재 equations for the correction of the axis dose rate through the aluminum therapy table were derived for most frequently used angle positions, and also an equation for conversion from aluminum thickness to tissue-equivalent material thickness was derived for Tissue-Air-Ratio calculation of sup <TEX>$^{60}$<TEX>Co teletherapy.