Secara umum, penelitian ini memberikan informasi mengenai data dan keterangan bahasa dayak kenyah uma alim dan bahasa dayak kenyah uma lasan untuk penelitian linguistik historis komparatif di indonesia dan secara khusus menganalisis adanya kekerabatan di antara kedua bahasa tersebut. penelitian ini menggunakan metode kualitatif dan kuantitatif. teknik yang digunakan adalah dengan menggunakan teknik leksikostatistik. metode dan teknik pengumpulan data dilakukan dengan metode observasi, wawancara, dokumentasi dan trigulansi. teori yang digunakan adalah linguistik historis komparatif yang memiliki peran utama salah satunya adalah menjelaskan hubungan kekerabatan suatu bahasa dengan bahasa yang lainnya di suatu wilayah yang ditentukan dengan menggunakan daftar kosa kata dasar morris swades yang berjumlah 200 kata. kata kerabat (kognat) dalam bahasa dayak kenyah uma alim dengan bahasa dayak kenyah uma lasan terdapat 187 kosa kata dasar swadesh, terdapat 81 pasangan kata yang identik, 34 pasangan kata yang memiliki korespondensi fonemis, 28 pasangan kata yang memiliki kemiripan secara fonetis, 44 pasangan kata yang memiliki satu fonem berbeda dan 13 pasangan kata yang tidak berkerabat. persentase kata kerabat antara bahasa dayak kenyah uma alim dan bahasa dayak kenyah uma lasan yaitu 93.5%. bahasa uma alim dan bahasa uma lasan merupakan bahasa yang tunggal pada 203 – 105 tahun yang lalu. bahasa uma alim dan bahasa uma lasan mulai berpisah dari suatu bahasa proto antara tahun 1.819 – 1.917 (dihitung dari tahun 2022). hasil penelitian menunjukkan bahwa bahasa dayak kenyah uma alim dengan bahasa dayak kenyah uma lasan termasuk ke dalam kategori satu bahasa (dialek). kata kunci: kekerabatan, linguistik historis komparatif, uma alim, uma lasan, leksikostatistik

The type of study is diacronic linguistics, comparing the dayak kenyah uma alim language with the dayak kenyah uma lasan language to examine the relationship between the two language. the study used qualitative and quantitative methods. the technique were observation, intervuew, documentation, and triangulation. the theory used was comparative historical linguistics, which played a major role. this consisted of using morris swadesh 200-word basic vocabulary list was to explain the relationship between the language of a particular region and other languages. the word kin (cognate) from dayak kenyah uma alim to dayak kenyah uma lasan includes 187 basic vocabulary words, 81 identical word pairs, and 34 word pairs with phonemic correspondences. contains 28 word pairs that are phonetically similar and 44 word pairs, a specific phoneme and 13 unrelated word pairs. dayak kenyah uma alim and dayak kenyah uma lasan have a cognate rate 93.5%. uma alim and uma lasan were a singel language 203-105 years age. the uma alim and uma lasan languages began to separate from yhe mother tongue from 1819 to 1917 (counting from 2022). research has revealed that dayak kenyah uma alim and dayak kenyah uma lasan are dialects. keywords: kinship, comparative historical linguistics, uma alim, uma lasan, lexicostatistics