The article is devoted to the analysis of existential-philosophical aspect and historical bases of the genre “joktau” (lament). The researcher shows that this genre inherited oral-poetic traditions of Sak, Hun, Uysun tribes and has deep roots of existential philosophy of Kazakh people. The author relies on the works of famous philosophers, folklorists and linguists in his research. According to the author's opinion, joktau reflects the humanistic worldview of Kazakhs about human existence and the meaning of each stage of the human life’s cycle “birth-growth-death”. The living tradition of joktau, along with its deep philosophical significance, demonstrates the genesis of folklore poetics and reflects the historical reality of the era in which it was created. The author emphasizes the world outlook connection of joktau with Kazakh myths and fairy tales. The text of «Joktau on Hajj Abdullah», which was found by the author in the manuscripts fund of the National Academy of Sciences is of great historical value. This oral-poetic text reflects the era of colonization of Kazakh lands by the tsarist power of Russia. Zhoktau describes how Kazakh tribes, that lost their lands, migrated from the eastern region of Kazakhstan and wandered in search of a home in Mongolia, China and Russia. The researcher notes that the joktau genre needs a deep study as it is an important monument of oral folk art, associated with the worldview, life philosophy and history of the Kazakhs.