The adsorption of cationic (methylene blue, MB) and anionic (Congo red, CR) dyes using magnetic from Archidendron pauciflorum peel extract obtained via sonochemical synthesis (Fe3O4-AP) has been carried out. This study also compared the ability of Fe3O4-AP as an adsorbent for MB and CR through isotherm and kinetics studies. Fe3O4-AP was synthesized by the sonochemical method at a frequency of 800 kHz and characterized using FTIR, XRD, PSA, VSM and SEM-EDX The XRD diffractogram showed Fe3O4-AP with high crystallinity with a crystal size of 17.05 nm, and the particle size distributed in three groups, 2.56, 862.23, and 4855.78 nm, respectively. Meanwhile, the Ms of Fe3O4-AP was 27.71 emu/g. The SEM-EDX showed disordered morphology with Fe, O and C elemental composition. The kinetics and isotherm of MB and CR dye adsorption on Fe3O4-AP followed Ho’s kinetics model and Freundlich isotherm. The Freundlich isotherm model with adsorption capacities MB and CR on Fe3O4-AP was 16.02 and 10.24 mg/g, respectively.