In examinations of the stomach roentgenography, it is imperative to obtain adequate film density throughout all its different regions. Therefore, it is necessary to use more sophiscated exposure techniques. In order to achieve these purpose, the radiologic technologists must be measured abdominal thickness in variations with patient positions. In consideration of these problem, the author was made an experiment on correction method of kVp and mAs by abdominal thickness in roentgenography of the stomach. The results were summarized as follws: 1. When the patient in erect position, abdominal thickness was the most thickened at the level of 3cm inferior to umbilicus without regard to body habitus and it was the most thickened at the level of 3cm superior to umbilicus in prone and supine position. 2. As a result of measuring film density for stomach, the adequate film density was represented from 0.70 to 2.49 in erect position and $0.28{sim}1.18$ in supine position, $0.5{sim}2.45$ in prone position. 3. In order to obtain uniform film density in 1.25, the correction factor for kVp by abdominal thickness was represented average ${pm}4.5kVp;per;{pm}1cm$ in a fixed 50 mAs, and average ${pm}3.9kVp;per;{pm}1cm$ in a fixed 100mAs. 4. In order to obtain uniform film density in 1.25, the correction factor for mAs by abdominal thickness was represented average ${pm}30.9%;per;{pm}1cm$ in a fixed 80 kvp and ${pm}26.9%;per;{pm}1cm$ in a fixed 100kVp.