Species diversity and distribution of oribatid mites (Acari: Oribatda) according to three habitat types and four vertical layers in the forest soil ecosystem of Cat Ba National Park, Hai Phong city were studied in the period of 2012-2013. Identified are 44 oribatid mite species, including 40 ones firstly recorded for the Cat Ba National Park, and two firstly recorded for the Vietnam fauna, namely Tegeozetes tunicatus breviclava Aoki, 1967 and Dimidiogalumna azumai Aoki. The species diversity and distribution of the soil oribatid mites can evaluated as a bioindicator of the chance of Vietnam's forest ecosystem.