1 Key Laboratory of Liquid Structure and Heredity of Materials (Ministry of Education), Shandong University, Jinan 250061, China; 
2 Section of Chemistry, Aalborg University, Denmark-9000, Denmark

The glass transition involves more than one dynamic relaxation mechanisms in supercooled liquids, such as α relaxation, slow β relaxation and fast β relaxation and so on. For the traditional theoretical system, α relaxation is believed mainly responsible for the nature of the glass transition as the beginning of the phenomenon. This idea, however, has been open to a big challenge since recent studies have indicated that slow β relaxation closely relates to α relaxation. Slow β relaxation determines the characteristics of α relaxation and is the precursor and the more microscopic base of glass transition behavior. In order to illuminate the significance of slow β relaxation in the fields of the glass transition and the structure of supercooled liquids, the accomplished progress is summarized from different aspects such as on the correlation between α relaxation and slow β relaxation, on the manner of α-slow β relaxation merging, on the energy landscape, on the excess wing and on the thermodynamically phenomenological mod-els. The tendency of investigation in slow β relaxation is also evaluated.

This work was supported by the National Natural Science Foundation of China (Grant No. 50801041), National Basic Research Program of China (Grant No. 2007CB613901) and Research Fund for the Doctoral Program of Higher Education of China (Grant No. 200804221041).