Abstract
Language changes and develops over the time. Language tends to be dynamic and diverse. It varies not only by region but also by culture, social class, and even age of some groups. This study aimed to analyze the differences on lexical and phonetic-phonological between Jujun and Keluru isolect of Danau Kerinci dialect of Kerincinese by using qualitative descriptive method. The study focused on the lexical and phonetic phonological features of Jujun and Keluru isolect. The data of this research was 207 words taken from Morris Swadesh and it collected from ten informants in total which were elder native speakers. This research used dialectometric formula from Mahsun (2005) to count the difference percentage from both isolect. The findings reveal that percentage of lexical differences in Jujun and Keluru isolect was 21.8%, and 86.5% for phonetic-phonological differences. Based on the percentage above, it can be concluded that lexical differences on Jujun and Keluru isolect categorized as speech difference while phonetic-phonological differences categorized as language differences according to Mahsun (2005) formulation. Both isolect has different vocabulary choices and different way in sound production.