Attributed to advanced structrual characterization techniques, mesoscopic hierarchical structures as well as crystal network structures are revealed in different varieties of soft materials including silk fibroin materials. Noting the close correlation between mesoscopic structures (especially the crystal network structures) and macroscopic performance of silk fibroin materials, comprehensive investigations on the formation of crystallites and crystal network are utmost important. Based on latest research studying on how silk fibroin molecules refold into higher levels of structures within silk fibroin materials, it is determined that the crystallization theory can well predict the formation process of silk fibroin materials and the corresponding kinetics. Nevertheless, the rational design and mesoscopic reconstruction of silk fibroin materials can be implemented by controlling the molecular crystallization, such as crystal density, orientation degree, doped molecular nucleation intiator and so on, which endows noval functions to silk fibroin materials and other soft materials.