An Expert System (ES) is a system that attempts to mimic human expertise by applying inference methods to a specific body of knowledge. One of the inference methods used in expert systems is Case Based Reasoning (CBR), which uses experience from the past in order to solve current problem. Steganography is the art of concealing the existence of information within innocent carrier. It includes a vast array of techniques, each differ from the others in its requirements and results. This research concerns with the development of an expert system, called Expert System for Steganography (ESS), to help in finding the appropriate Steganography implementation that satisfy the user needs. ESS uses CBR to be able to suggest the closest implementation to user needs if no identical one is found. Also, if the system reached a situation in which several implementations are satisfactory, then it can break the tie by returning to the quality of the implementation, and hence suggest the best one. To accomplish the research, Steganography domain is analyzed to extract salient features for Steganography implementations and to create quality assessment measure.