Abstract: The sharp decline in natural habitats in the process of urbanization is the direct cause of biodiversity loss. The historical remnant habitats can be seen as the “core habitats” which play an important role in supporting urban ecosystem services. Using Seoul (the capital of South Korea ) as a case study, we firstly identified the “core habitats” through 4 years land-use and land-cover maps and selected 22 sample parks, then quantified landscape metrics and habitat quality using Fragstat software and InVEST model. The results show that: 1) The habitat quality of forest-habitats adjacent to the built-up areas is significantly lower than that of the areas in urban fringe. 2) The effects of habitat sizes on the values of habitat units indicate the scale-dependence. Compared with the large-scale sample patches, the “core habitat” unit values of small-scale and medium-scale patches are less affected by their size. 3) The main impact of the landscape pattern of sample habitats on the quality of “core habitats” can be summarized as the factors of shape and the factors of aggregation (the interpretation degree of the factor analysis is 96.022%), featuring a significant linear regression relationship.