Abstract—The adsorption behaviors of sulfur atoms on Pd (111) surface have been investigated by Scanning Tunneling Microscopy (STM). After the clean Pd (111) surface is exposed to different doses of H₂S at room temperature. The direct STM results of one monolayer adsorption show the terraces of Pd surface are dominated by  Pd (111)-S while a mixture of small area of  , disordered S and  stripes distributes along the step edges. Excess one monolayer adsorption results in minor change for the proportion of different structures. The evolution of S induced reconstruction with the annealing temperature are also investigated by STM. After annealing to 370K, most of   reconstruction on the terrace are converted into . Heating to 420K and 470K favors the missing of more and more sulfur atoms at the area of   while no obvious change occurs in the  area. The corresponding models are given for three observed ordered reconstruction structures.