PAN style="FONT-FAMILY: ’Times New Roman’,’serif’" lang=EN-US>The Yueyashan-Xichangjing ophiolite, located at the middle section of the Beishan area, is one of the well exposed ophiolitic belts in the Beishan area. The pillow basalt and cumulate gabbro are characterized by depletion of LREE, flat distribution pattern, and minor-fareast; mso-hansi-font-family: ’Times New Roman’; mso-bidi-font-family: ’Times New Roman’">（La/Ybminor-fareast; mso-hansi-font-family: ’Times New Roman’; mso-bidi-font-family: ’Times New Roman’">）N=0.47minor-fareast; mso-hansi-font-family: ’Times New Roman’; mso-bidi-font-family: ’Times New Roman’">～1.62, similar to those of N-MORB. And by enrichment of LILEs, and depletion of HFSEs such as Nb and Ta, different from those of N-MORB, but similar to those by typical island-arc volcanic rocks, i.e., the mafic rocks have both the MORB-like and arc-like geochemical features. Combined with the geochemical and sedimentary characteristics, it can be concluded that the Yueyashan-Xichangjing ophiolite may form in a back-arc basin, which, along with Xieshan-Dongqiyi volcanic arc in the north of the basin, constituted an “arc-basin” system in the Tarim Plate.