The Jiesha mafic-ultramafic body is distributed mainly in the eastern Yarlung-Zangbo suture zone of Tibet. The massif consists of harzburgite, dunite, and podiform chromitite. Chromitite orebodies with a length of 20~40 m and a width of 1~3 m trend from east to west and dip northwest. The surrounding rocks are mainly harzburgites and dunites. Microscopic characteristics and electron microprobe analysis show that the chromian spinel in the Jiesha chromite has Cr# of 679~885 and Mg# of 646~682, with TiO2 content of 006%~018% and Al2O3 content of 131%~165%, suggesting that the Jiesha chromite is high-Cr type chromite Mineral chemistry of olivine, orthopyroxene and clinopyroxene in harzburgite shows that the Jiesha harzburgite are similar to abyssal peridotite and the fore-arc peridotite Based on the chemical composition of spinel-olivine/clinopyroxene, it can be identified that the Jiesha mafic-ultramafic body had experienced early partial melting (degree about 20%～30%) and late rock/melt reaction (degree about >35%) Therefore, the Jiesha peridotites and chromite, like other rock bodies in the Yarlung Zangbo suture zone, might experience multi-stage superimposition processes such mid-ocean ridge （MOR） and late suprasubduction zone （SSZ）