Abstract: It has become increasingly clear that the occurrence of species and their population densities, as well as population dynamics, trophic interactions, and community structure within a habitat, may depend on processes of large spatial scales. The destruction and fragmentation of habitats has become one of the major threats to biodiversity. At first, the characteristics of habitat fragments (patches) in relation to possible processes and patterns of insect communities and their mechanisms for influencing diversity and biotic interactions were introduced based on literature surveys. The effects of habitat fragmentation on the structure, richness, and interactions of insect communities, and population dynamics with special emphasis on grassland landscapes were summarised and sorted in order. Experiments on the characteristics and dominant natural conditions in fragmented habitats and investigations in grassland habitats were conducted. This study showed that the relationships between patterns of fragmented habitats and biotic interactions, and secondary succession series in grassland landscapes were the key to the question of biodiversity conservation.