There is a set of calcicalkalic volcanic rocks with basalt-andesite in the northeast part of Bogda orogenic belt. The measured zircon 206Pb/238U age, 314.7±1.5Ma, by LA-ICP-MS, shows that the volcanic rocks formatted in Late Devonian. Their SiO2 changes in a narrow limits and they are featured with higher Al(Al2O3=15.81%~17.74%) , lower TiO2(TiO2=0.99%~2.44%), and being rich in Na(Na2O=2.82%~3.82) and deficient in K(K2O=0.17%~1.62%). Their REE abundance is from 103.75×10-6 to 137.26×10-6, with a rightly-oblique patterns type characterized by LREE enrichment and HREE depletion and a negative anomaly of Eu. In primitive mantle-normalized multi-elements spider diagram, they are enriched selectively with large-ion-lithophile elements (LIEL) such as Ba and U, uniformly and observably depleted high-field-strength elements(HFSE) such as Nb,Ta, Ti and Y, being similar with the geochemical characteristics of arc volcanic rocks. But their Nb/U, Nb/Th, Th/U have an affinity for N-MORB. The samples’ Mg#=54.46~64.34, Ni=73.56×10-6, Cr=156.37×10-6 and the same variation trend in TFe2O3 and TiO2 with SiO2 indicate that the magma have a process of crystal fractionation including Ti-Fe oxide. The correlation of La/Nb-Sr, Nb/Ta-La/Yb and the ratio of (Th/Nb)N, (Nb/La)N indicate that the magma suffers from the mixing of the crust. The simulation curve and Zr-Zr/Y diagram imply that the basalt formatted in intraplate, and its magma source is situated in the spinel stability field. It is the products of asthenosphere mantle/mantle medge melting with decompression in backarc basin. The age and situation of the volcanic rocks and the background of regional geology, reveal that the volcanic rocks in the northeast part of Bogda orogenic belt is the reflection of Kangguertage ocean subducting northerly, and provide a new evidence for the viewpoint that the Bogda Carboniferous rift valley should evaluate from the backarc basin for Kangguertage ocean subducting to Turpan-Hami plate during Early Paleozoic to Late Carboniferous.