Seed dispersal is critical ecosystem process affecting plant population dynamics and community structure. In endozoochory, the ecological characteristics of the dispersal agent is one of determinants of dispersal mechanism. To understand the different roles of members of disperser assemblage in seed dispersal networks, it is essential to focus the network structure and landscape seed deposition occurs. Our research purpose was to assess both quantitative and qualitative aspects of a mammalian endozoochorous seed dispersal network in temperate forest ecosystem. We hypothesized that (1) the probability of dispersed seeds, their abundance and species richness differed among dispersal agents; (2) the probability of dispersed seeds towards suitable microsites and their abundance varied among dispersal agents; (3) the environmental factors at deposition sites varied among dispersal agents; (4) complementary structures occur in the seed dispersal network in terms of dispersers, dispersed species, and deposition sites. Our results show that quantity and quality components varied among dispersers and seasons. Furthermore, there are specialized and modular network structures between mammals–plants and mammals–deposition site environments. It is because mammals have different food habits and behavioral traits even if they are generalist frugivores. The differences in ecological characteristics possibly lead to complementary relationships across landscapes.