In this study, ten different bio-adsorbents were prepared by immobilization of vegetable tannins such as mimosa(catechol tannin) and chestnut(pyrogallol tannin) on the collagen matrix which was derived from leather manufacturing process. Removal efficiency of Au(III) by each bio-adsorbent in synthetic wastewater was evaluated by a laboratory-scale batch experiments at different reaction conditions. When mimosa was used as a vegetable tannin, the penetration efficiency of it in the inner bundle of fiber increased at higher dose of the naphthalene condensated penetrant. For all bio-adsorbents, removal of Au(III) increased as the solution pH decreased. Most bio-adsorbents showed a near complete removal below pH 3. Au(III) adsorption was slightly increased as the ionic strength increased. Au(III) adsorption onto bio-adsorbents was little affected by the presence of background electrolytes having mono-valent and di-valent anions, however, was significantly retarded at the presence of phosphate.