In Japanese national parks,the designation of a park and its zoning boundaries is influenced by land ownership. There has been criticism that zoning is influenced by timber production or other commercial activities. We examined the relationship between the national park plan and national forest plan in the Shikotsu-Jozankei area in Shikotsu-Toya National Park. We overlaid the national forest management plan map with the park plan map using a GIS. We found that half of the park boundaries have commonality with a national forest unit and 36% with municipal boundaries. The special protection zone and special zone I of the national park plan are similar to the Protection Forest in a national forest. Special zone II is similar to the Recreation Forest in a national forest. National forest functional zones have many similarities with national park zoning. These results clarified the significant effect of a national forest plan on the definition of national park zoning.