Abstract: The modified asphalt was prepared by adding different mixing amounts of diatomite-cellulose composite fiber.In order to research the modified mechanism,the microstructure of matrix asphalt and DCCF modified asphalt was analyzed by FT-IR and DSC.The results showed that there was no chemical reaction between DCCF and matrix asphalt.The DCCF uniformly dispersed in the asphalt,and selectively adsorbed components of asphalt,making the colloform texture of asphalt retuned,the form and quantity of some components in asphalt changed.These changes altered the microstructure of asphalt and decreased amount of the congeries state.Thus the temperature susceptibility of the DCCF-modified asphalt was improved obviously.DCCF modifying asphalt was a physical enchase blending process,during which the microstructure of asphalt was improved.

Key words: DCCF, Microstructure, Modification mechanism, FT-IR, DSC