This paper describes a new recording script generation method that can create speech databases for corpus-based TTS systems. This method is efficient due to its two features; (1) It has a 2-stage algorithm to generate the recording script with consideration of the balance of triphone, syllable and morpheme elements. (2) It can control types of phonetic elements included in the recording script via the weight coefficients of the phonetic elements. An evaluation shows that the 2-stage algorithm is effective in raising the coverage of phonetic elements and that this method yields a recording script containing various phonetic elements. A preference test shows that changing the selection criteria influences the quality of the synthesized speech. The same test also shows that it is better to take account of morpheme-based elements than syllable-based elements in generating a task-specific recording script.