Early Ordovician and Early Silurian are the key periods for the evolution of tectonics and basin in the North Qilian Caledonian orogenic belts. The characteristics of trace and rare earth elements for the  sandstones from the Lower Ordovician Yingou Formation and Lower Silurian Angzanggou Formation in Jingtai area were presented. The greywacke samples(Cj1 and Cj3) from the Yingou Formation are  characterized by minimal Eu/Eu* and maximal values of  Th/Sc and REE. In contrast, the lithic sandstone samples(Cj13，Cj15 and Cj18)from the Yingou Formation，possess maximal Eu/Eu*，  minimal values of Th/Sc, ∑REE and La/Yb， and the greywacke samples of Angzanggou Formation have intermediate values of Eu/Eu*，Th/Sc and REE. Employing diverse plots of provenance and tectonic setting discrimination and multielement diagrams，this study shows that(1)the lower part of the Yingou Formation，represented by the greywacke samples of Cj1 and Cj3, was mainly derived from the recycled deposits and felsic sources in the upper continental crust with the tectonic setting being the continental margin and  the middleupper part of the Yingou Formation，represented by the lithic sandstone samples of Cj13，Cj15 and Cj18，from the maficintermediate andesitic sources in an island arc environment，with a probable tiny supply from continental margin materials;(2)with regard to the  Angzanggou Formation，it was deposited in a complex tectonic setting where the continental island arc，active continental margin and passive continental margin coexisted. The sediments were derived from mixed sources of maficintermediate volcanic arc，felsic rocks and recycled sedimentary rocks. The two suits of sandstones may be sourced from similar sources. The constraining on the sources of sandstones shows that(1)the potential source for furthermore, the greywacke samples were probably derived from the metasedimentary rocks of the Haiyuan Group lying in the southern margin of Alashan Block and other recycled terrigenous sediments with a comparable property to the former. The lithic fragments in the lithic sandstone samples are dominated by volcanic island arc materials and they are comparable with the maficintermediate volcanic rocks in the early stage of the Shihuigou Arc，which suggests that the Yingou Formation was deposited in an incipient backarc basin mirroring the action within the island arc;(2)the sediments in the  Angzanggou Formation were probably sourced from the metasedimentary rocks of Haiyuan Group in the south margin of Alashan Block，the island arc volcanic rocks with moderatehigh maturity in Shihuigou area and the island arc metavolcanic rocks of the Haiyuan Group. The Angzanggou Formation was deposited  in a retroarc basin，reflecting the tectonic setting with a hysteresis. 