1. Purpose : 30 patients with uterine cervical cancer who had been treated at Department of radiation Oncology of Korea university Hospital from June, 1, 1994. to December. 31, 1994. were analyzed to the radiation field accuracy using verification films. 2. Methods and Materials : 30 patients were divided by 6 groups, 5 patients respectively : Group (1) : Standard physique, supine not-fixed Group (2) : Standard physique, supine fixed Group (3) : Obesity physique, supine, not-fixed Group (4) : Obesity physique, supine, not-fixed Group (5) : Obesity physique, prone, not-fixed Group (6) : Obesity physique, prone, fixed All groups were taken verification fimls during the whole treatment period, and it compared with simulation films and portal fimls, 3. Results : This results suggest that all patients should be immovilized and especially obesity physique patients should be treated by prone position in order to reduce radiation field discrepancy. In addition, this results should help to prescribe appropriate safty margins for patients simulation.