Diversity of forest soil invertebrate assemblages was investigated in Shimentai Nature Reserve where lies a transition zone between the southern subtropical zone and the middle subtropical zone in September and October 2001. A total of (20 045) soil invertebrate individuals which belong to 89 families (including microdrile oligochaetes, mesogastropoda and acarina etc.) of 25 orders in 9 classes under 3 phyla was collected. Of the collected specimens, Acarina and Collembola (mainly Isotomidae, Entomobryidae, Onychiuridae and Neanuridae), accounting for 66.0% and 13.7% of the total collected individuals, respectively, were the dominant groups of forest soil invertebrate assemblages in Shimentai Nature Reserve, Thysanoptera (Phlaeothripidae) and Hymenoptera (mainly Formicidae) are the ordinary groups in this region and constitute 6.8% and 5.8% of the total collected individuals, respectively. Shannon-Wiener diversity index and Density-Group index were used to compare the diversity of soil invertebrate assemblages in two different habitats (natural evergreen broad-leaf forest and planted forest). The results showed that the diversity of soil invertebrate assemblages in natural evergreen broad-leaf forest was much higher than that of planted forest impacted by human activity (P<0.05). Using Density-Group index to measure the diversity of soil invertebrate assemblages is more reasonable than Shannon-Wiener diversity index in this case because the Acarina individuals predominate in the samples which covers up the information of other soil invertebrate groups.