Abstract: Niuheliang archaeological site is an important site of Hongshan Culture. To preserve the cultural and historical value, it is decided that this site should be preserved and displayed in open air. To counteract the sordid environment, three kinds of chemical materials are selected as strengthening medium. The chemical materials chosen are non-aqueous dispersion and organosilicone. The clay samples from the same site strengthened by these materials are tested in the laboratory to check the variation of weight and color, compression strength, water decomposition, freezing-thaw resistance and salt tolerence in order to compare the strengthening effect. The conclusion is that the non-aqueous dispersion behaves better in the tests. Two kinds of non-aqueous dispersions are tested in the site. The test results show that the non-aqueous dispersion is the first choice as strengthening medium.