Indonesian regional indigenous languages are in decline and their conservation faces considerable challenges. One possible challenge is speech level. This paper aims to describe the existence of speech level in some regional indigenous languages and its possible implication for their conservation. The method comprises policy study, particularly documentary study. The sample included three languages, i.e., Sundanese, Balinese, and Javanese. The result shows the existence of speech level in the three languages. For example, the Javanese language at present has 4 levels, namely, high krama, krama, high ngoko, and ngoko. On one hand, the existence of the speech levels enriches structure and vocabulary. On the other hand, these levels make it difficult for new learners and speakers, particularly the younger generation, to master the languages. This may constitute a constraint for their conservation. Therefore, language experts and speakers of these languages need to consider corpus planning effort to simplify the speech levels in order to ease the difficulty of mastering the languages and support their conservation effort. For Javanese language, ngoko alus is recommended as the standard usage.