During recent decades, habitat fragmentation is one of the most serious impacts for biodiversity in anthropogenic landscapes. Because the distance that causes fragmentation varies with species, it is difficult to make management plans to maintain connectivity by single-species. Therefore, it seems practical to evaluate the candidate set of the species which would be the most seriously affected by habitat fragmentation from the landscape structure itself, because the degree of landscape connectivity is determined by spatial configuration of habitat patches alone. Although the degree of landscape connectivity varies with landscape units, previous studies have been carried out only in single units selected by the researcher. In order to provide effective land management plan, clarifying suitable landscape unit for assessing landscape connectivity is needed. Considering habitat types with landscape connectivity is another important issue. Because origin factors differ among habitat types, each type may have different roles in habitat network. However, most previous studies have not considered the difference in habitat type. The aim of our study is to assess landscape connectivity using GRAPH THEORY. By focusing on forests in agricultural landscape, we clarify 1) suitable landscape unit to assess landscape connectivity, and 2) how each forest type contribute to forest connectivity.