Abstract: Based on the precise biostratigraphic work and combined with fossil biota and their geological periods, it is redefined the sequence in Silurian -Devonian lithostratigraphic units in southern margin of the Kalamaili collision zone, east Junggar. The result shows that the assemblages of fossil biota in the first section of the Baishanbao Formation in middle-upper Silurian can be established as Tuvaestrophia sp. - Leptostrophia sp. -Protochonetes sp, the second and third sections can be established as Tuvaella gigantea Tschernyschew--Atrypa cf. depressa Zhang-Stegerhynchus sp. and Tuvaella gigantea Tschernyschew- Tuvaella rackovskii Tschernyschew- Leptaena cf. depressa- Tannuspirifer xinjiangensis Zhang., respectively. The assemblages of fossil biota of the Laogou Formation in upper Silurian can be established as Atrypella cf. columbella Barrande- Athyrisina cf. uniplicata Grabau - Stegerhynchus angaciensis Tschernyschew, the Hongliugou Formation in lower Devonian can be established as Steatothamnopora sp. - Striatopora sp. - Parathamnopora sp. and Kalamaili Formation of lower-middle Devonian is established as Leptocoelia cf.sinica Su- Enterolasma sp. - Diplochone sp. In addition, Prelepidondron sp. is discovered in Keankuduke Formation in upper Devonian. The establishment of biological stratigraphic units in Silurian-Devonian in this area is important to study the Silurian-Devonian biostratigraphy in Kalamaili collision zone