The developing temperatures dependency of the physical imaging properties of KONICA HI ORTHO EXCELLENT SYSTEM (EX system) and KONICA MEDICAL SUPER RAPID SYSTEM (SR series) was evaluated by measuring characteristic curves, resoluion properties and noise RMS. Futhermore, the possibility of a reduction of patients' radiation exposure without a decrea s e in imaging qualities was evaluated because the speed of screen / film systems increase as the developing temperature going up and the granularity of the EX system is greatly improved comparing with SR series. The physical imaging properties of screen / film systems were affected by the developing temperature. But the level of the effects on EX system was smaller than SR series. It was confirmed that the granularity of the EX system was improved greatly compared to SR series. Therefore, there is the possible reduction of patients' radiation exposure b y increasing the developing temperature compared to the actual situation.