In this paper, a peroxide-tertiary amine oxidation-reduction initiator system was used to synthesize a cross-linked polyacrylamide/bentonite composite at room temperature. The composite could contain up to 50% bentonite. Performance studies showed that the salt tolerance of the composite was enhanced compared to bentonite. The structure of the composite was characterized and analyzed by XRD, FTIR, and TG. Other than a slight increase in the interlamellar spacing, the structure of bentonite did not change during its aggregation. The composite therefore had enhanced dispersion properties and improved thermal stability.