Abstract: The basic physical and chemical properties of bentonite in the northwest of Sichuan province were evaluated in this paper.Water purifying agent from bentonite mixed with other materials is processed through the acid active reaction on the low temperature.The cleansing ability of water purifying agent were evaluated in the paper.The synthetic process,principle and conditions of 5A zeolite sieve with bentonite were also studied in this paper.The structure of 5A zeolite was test by x ray affraction and differential thermal analysis.The related properties of 5A zeolite were evaluated.