Abstarct: In this research, sulfur functionalized graphene oxide composite (GO-S) was prepared from the reaction of graphene oxide with sodium thiosulfate in hydrochloric acid environment. This composite was identified using conventional methods such as Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (FE-SEM) and X-ray energy diffraction spectroscopy (EDS). GO-S composite was used in the process of cadmium ion absorption from aqueous solution. The absorption process of cadmium ion by GO-S adsorbent and the influencing factors such as solution pH, contact time, amount of adsorbent used, concentration of cadmium solution and reaction temperature were investigated. The percentage of cadmium ion removal and adsorbent capacity under optimal conditions (pH equal to 8/0, contact time 15 minutes, amount of GO-S adsorbent 0.015 g, concentration 20 mg/l and temperature 15 degrees Celsius) respectively equal to %86/5 and 57/66 mg/g was GO-S adsorbent. The results show that the absorption process of cadmium ion by GO-S corresponds to pseudo-second-order kinetics and the Langmuir adsorption model can also be considered for it.