We used the following criteria for natural geographic division of the protected area:
- vegetation cover
- fauna
- orographic division
- geological structure
 

Geography
Kozjanski Park consists of three natural-geographic units:

• the eastern part of the Posavje hills, consisting mainly of dolomite and limestone. The highest points are between 500 and 800 metres (the Kunšperk hill, the Orlica, the Vetrnik, the Oslica and the Rudnica)
• the hills in the middle part of the Sotla valley and the Bizeljsko hills, consisting mainly of sandstone, marl, sand and an exceptionally large area of lithotamnic limestone (Virštanj, the Bučka gorca hill, the Trebča gorca hill, Črešnjevec, the Bizeljsko hills and the Sromeljsko hills),
• the plain in the Sotla valley, consisting mainly of sand, clay and gravel Quaternary alluvium (the Imensko polje, the Bučko polje, the Bistriško-Kunšperško polje, the plain along the Sotla and south of Bizeljsko)

Vegetation cover
According to the phyto-geographical division of Slovenia (Zupančič & Žagar, 1995), Kozjanski Park spreads across three vegetation zones. This is why the botanic elements within the Park are highly diverse.

• the sub-Pannonian zone with regions Haloze and Bizeljsko-Krško
• the sub-Alpine zone with the regions Styria and Carinthia
• the sub-Dinarid zone with regions Bohor-Kum and Middle Dolenjska

Fauna
According to the zoo-geographic division of Slovenia, the area of Kozjansko belongs to 2 major regions:

• the sub-Alpine
• the sub-Pannonian

The Karst-sub-Pannonian subregion is only a few kilometres from park’s boundary in Senovo.