This paper describes a concept description scheme for speech synthesis. It is input to the synthetic speech output interface connected to various performance systems, and used for direct derivation of prosodic parameters. The concept description is composed of atomic symbols, templates and operators represented in terms of appropriate abstract level of constructs and makes it easy to generate both sentences and prosodic parameters. There are two built-in mechanisms in the templates for directly controlling the prosodic parameters. The first one is the pause marker which is generated along with words in the sentence generation. The pause marker is used to insert pauses and to locate boundaries of phrase component of pitch. The second one is the Prosody Modification Functions (PMF) embedded in the custom templates. PMF controls the the prosodic parameters for the prepared sentence pattern.