Apatite is a ubiquitous accessory mineral in many geological settings and is stable over a wide range of pressure and temperature. With halogens, rare earth elements (REEs), strontium, yttrium and other minor elements, apatite can reflect the formation of rocks and change of fluid composition. Apatite is one of the most common accessory minerals in eclogites and high pressure veins from HP-UHP metamorphic belt in Chinese southwest Tianshan Mountains, Xinjiang. The occurrences of apatites include inclusions, intergranular grains and vein apatites. This study mainly focused on the apatites whose diameters are larger than 0.1 mm and which were formed at or after the stage of peak metamorphism. According to the results of major element analysis, all the apatites are fluorapatites. The concentration of fluorine ranges between 1.44% and 3.56%, and that of chlorine is below 0.09%, which suggests that the salinity of the fluid in equilibrium with apatites is low. The results of LA-ICP-MS analysis suggest that all the apatites have relatively high concentrations of Sr, Y and REEs, low concentrations of large ion lithophile elements (LILEs, such as Rb and Ba) and high field-strength elements (HFSEs, such as Zr, Nb, Hf, Ta and Ti), and various values of total rare earth elements (∑REE) from 10×10-6 to 660×10-6. Based on the ∑REE and their differentiation, all the samples can be divided into three types: LREEs enrichment with low ∑REE, flat pattern with medium ∑REE and MREEs enrichment with high ∑REE. An euhedral elongated apatite displays a growth zoning with the concentrations of REEs gradually decreasing from core to rim, which may reflect the growing process of the apatite and change of fluid composition.