This paper presents the first results on the Mo Piu tonal system. This language is undocumented, unwritten and moreover in great danger. As the tasks of labeling phonetics and tones is hard to carry out when references on the language are lacking, this paper aims at presenting our method to try to build reliable data in order to understand the tonal system, and the main findings concerning the Mo Piu tonal system and finally at leading a comparison between these first results and the White Hmong tonal system.

Index Terms: undocumented language, tonal system, isolated words, automatic tones labeling.