The article provides a comparative analysis of the flora and endemism of the western and eastern part of the KetpenTemerlik range in Kazakhstan and China, which is the eastern tip of the Northern Tian Shan. The flora of the entire Ketpen-Temerlik range includes 1890 species of vascular plants belonging to 593 genera and 120 families. In the western part of the ridge (in Kazakhstan), 1747 species were identified, belonging to 585 genera and 111 families and in the eastern part (in China), 1673 species belonging to 577 genera and 117 families. Angiosperms make up 98.4% of the ridge flora, 80.0% of which are dicotyledonous and 18.5% are monocotyledonous. The analysis of the largest flora families of the entire Ketpen-Temerlik range allowed us to identify 28 of the largest families by the largest number of species. The families with the largest number of species are Asteraceae (308 species), Poaceae (166), Fabaceae (133), Brassicaceae (105), Caryophyllaceae (93), Rosaceae (90), Lamiaceae (81), Chenopodiaceae (75), Ranunculaceae (74) and Scrophulariaceae (57). The major genera are Astragalus (43 species), Artemisia (38), Taraxacum (34), Carex (33), Allium (33), Potentilla (31), Ranunculus (22), Oxytropis (21), Veronica (20), Poa (18), and Saussurea (18).