The Xiaobaozhuang iron deposit, located in the Lujian-Zongyang volcanic basin, Middle-Lower Yangtze River metallogenie belt, is one of important porphyry-like type iron deposits found in recent years. Based on detailed field geological investigation and petrographical study, this paper analyzed the wall rocks and main ore minerals using EPMA, ICP-MS, sulfate isotope and fluid inclusion. The results show that the δ34S values of pyrites and gypsums formed in different mineralization stages are abnormally high, with δ34S of pyrites ranging between 6‰ and 15‰ and δ34S of gypsums from 16‰ to 24‰. The δ34S values of pyrites and gypsums decrease gradually with the depth from deep to shallow and alterationmineralization stage from early to late. The δ34S value of gypsum is 30.1‰ in the Middle Triassic sulfate evaporates salt layers, reflecting that there was addition of sulphur from gypsumsalt layers in the Xiaobaozhuang iron deposit. Microthermometry results show that the homogenization temperatures of fluid inclusions in diopsidemagnetiteanhydrite stage, epidote stage, carbonateanhydritepyrite stage and anhydritequartzpyrite stage are 326~496℃, 259~317℃, 178~280℃ and 107~189℃, respectively, and salinities are 14%~21%NaCleqv, 11%~20%NaCleqv, 6%~16%NaCleqv and 2%~13%NaCleqv, respectively. These features suggest that oreforming fluids experienced a process from high temperature and high salinity to low temperature and low salinity. Compared with the Luohe iron deposit from the characteristic of metallogenic rock, ore body, ore, alteration zoning and metallogenic temperature, the Xiaobaozhuang iron deposit and Luohe iron deposit are two independent deposits. The spatially superimposed structure of Xiaobaozhuang iron deposit and Luohe iron deposit may result from the emplacement of dioritic magma at different depths.