An aluminum salt-containing resin powder of the present invention includes at lest one matrix resin component selected from regenerated collagen, polyvinyl alcohol and carboxymethyl cellulose； and an aluminum salt. The aluminum salt is chemically bonded to the matrix resin component, and the resultant is powdered. A resin composition of the present invention includes 0.1 wt% or more and 80 wt% or less of the aluminum salt-containing resin powder and 20 wt% or more and 99.9 wt% or less of a resin other than the aluminum salt-containing resin. Thus, the present invention provides an aluminum salt-containing resin powder having a high phosphorus adsorption property, a high antibacterial property and a high antifungal property, and a resin composition containing the aluminum salt-containing resin powder.
