Radiographic images can be evaluated by the theory of entropy. This study is an evaluation about the process of development with the theory of entropy. As a result, the following was found on the transmitted information. 1. The system of development in a long time with low temperature is more superior than the system of development in a short time with high temperature. 2. The automatic processor has a difference by its variety of units. 3. It is better to use high temperature in development with the 90 seconds automatic processor. In conculusion, the best temperature is 33〜35℃.
