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The Baiyangping Cu-Ag polymetallic ore dis-trict is located in the northern part of the Lanping-Simao foreland fold belt,between the Jinshajiang-Ailaoshan and Lancangjiang faults,and the deposit can be divided into eastern and western ore zones.Based upon microscope observation of ore minerals and analysis of zinc,copper,and strontium isotope composition,we conclude that:(1)the zinc isotopic compositions of sphalerite from the eastern and western ore belt of the Baiyangping poly-metallic ore deposits are enriched in both the heavy(-0.09‰ to+0.15‰)and light(-0.19‰ to-0.01‰)zinc isotopes.Rayleigh fractionation is likely the additional factor controlling the observed temporal and spatial vari-ations in zinc isotopes in the two studied ore zones.The zinc isotopic composition in the Baiyangping polymetallic Pb-Zn deposits may have the same fractionation as that of magmatic-hydrothermal,VHMS,SEDEX,and MVT deposits,as demonstrated by geological and other geo-chemical evidence;(2)the range of δ65Cu in massive tetrahedrite is from-0.06‰ to+0.12 ‰ that relates to the early stages of ore-formation,which are higher than that of venial chalcopyrite(from-0.72‰ to-0.07‰)formed at a late ore-forming stage in the western ore belt.Different ore-forming stages and alteration or leaching processes are likely the main factors controlling the observed variations in copper isotopes in the western ore zone;(3)the 87Sr/86Sr value of hydrothermal calcite in eastern(0.7080-0.7093)and western(0.7085-0.7113)ore belt suggested that mineralization of early calcite,with 87Sr/86Sr values much higher than in ancient Late Triassic seawater,may be related to recrystallization from a radiogenic Sr-rich or silicifying fluid,either from the strata that the ore-forming fluid flows through or from other fluids.