A carrier for holding a microorganism in soil releases, from a constituting material thereof, an inducer for production of an enzyme of the microorganism for soil remediation. The carrier for holding a microorganism may comprise a combination of a microorganism holding carrier composed of a hydrophilic polymer for holding the microorganism with an inducer-holder composed of another polymer for holding inducer manifesting a biological action to the microorganism adjacent to each other. A method for remediation of soil comprises application of the microorganism-holding carrier into the soil. A soil-remedying agent comprises the microorganism-holding carrier and a microorganism held thereon which exhibits enzyme activity for decomposition of a polluting substance in the soil under action an inducer released by the carrier.