A new anti-swelling agent was synthesized by polymerizing epichlorohydrin and dimethyl amine polymer. The swelling inhibition properties were investigated over clay and shale. It was found that the clay inhibition of swelling properties was greatly enhanced compared with common inorganic salts. However, to shale, the swelling properties did not inhibited efficiently by using prepared polymers. Furthermore, the influence of cross linking of polyammonium to the swelling ability of prepared polymer has been also carried out by using triethylenetetramine cross linking agent. In the case of shale, the swelling inhibit properties was improved after cross link, while opposite swelling effect was observed over clay.