In　this　paper,　four　kinds　of　agents　(2000　polyethylene　glycol　(pg2000),　aminosalicylicacid　(ASA),　saodium　alginate　(SA),　sodium　metasilicate　anhydrous　(SMA))　were　investigated　as　potential　anti-clay　agents　combined　with　polycarboxylate　water　reducer　(PCE),　and　the　fluidity,　compress　strength,　and　flexural　strength　of　cement　paste,　mortar,　and　concrete　containing　aforementioned　anti-clay　agents　were　tested.　It　found　that　among　the　tested　potential　anti-clay　agents,　PG2000　have　performed　well.　The　fluidity　of　the　concrete　with　PG2000　increased　16mm　compared　to　the　control　sample.　In　order　to　understand　the　mechanisms　underlying　this　improvement,　X-ray　Diffraction(XRD)　of　cement　paste　was　carried.　The　results　show　PG2000　has　the　highest　interlayer　spacing(d=2.865142nm)　compare　with　control　sample(d=2.828410nm)　(not　added　PG2000),　which　make　it　more　effective　on　the　fluidity　of　concrete.