The b-glucuronidase (GUS) gene was first cloned in 1987 [19] , and in subsequent years, many GUS genes were cloned and registered in the GenBank. However, this gene has never been cloned for the hydrolysis research of GL into GAMG or/and GA, with more valuable merits. Based on CDD analysis, the three domains of the enzyme AtGUS were well investigated, and the main aim of the present study is to modify the non-conservative sequence of AtGUS and try to obtain an artificial evolution enzyme with better enzymatic properties.