The present invention relates to a method for preparing an adsorbent for phosphorus adsorption and an adsorbent prepared by the method. More specifically, the present invention is based on the fact that phosphorus has a strong affinity for the surface of metal oxides or hydroxides, and relates to a method for preparing an adsorbent for phosphorus adsorption, which comprises absorbing and coating expanded vermiculite with aluminum and heating the coated vermiculite at high temperature to produce aluminum oxide on the surface of the expanded vermiculite so that the adsorption of phosphorus at the coordination of the oxide can be achieved with very high efficiency by a strong attraction between phosphorus ions and aluminum ions, and to an adsorbent prepared by the method.