Abstract: Aiming at improving the properties of bentonite and expanding its use,the structure of bentonite and the theory and methods of modification for the unique lamellar layers of bentonite were introduced as well as the modified bentonites,such as sodium bentonite,activated bentonite,organically modified bentonite,and bentonite nanocomposite were prepared.Applications and prospects of those modified bentonites used in environmental protection and carrier materials and other fields were analyzed. Properties and quality of bentonites were improved greatly by modification,thus changing the situation of low quality and limited application of bentonite,helping to fully use the rich bentonite resources in China,increasing its added value,and creating greater economic benefits.

Key words: bentonite, modification theory, modified bentonite, environment-friendly materials, carrier