Diversity of ground beetle (Coleoptera: Carabidae) assemblages and sub-assemblages was compared between reafforested woodland, grassland, and intensively cultivated fields at Chongli County in Northern China. An array of eight pitfall traps per plot was used to sample the beetles on four replicate plots for each habitat. Replanted conifer woodland and semi-natural grassland harbored very similar beetle assemblages. These had significantly lower rarefied species numbers than the distinctly different assemblages recorded in cultivated fields, with differences in alpha diversity being less pronounced for large and predatory species. Carabid activity-density levels were higher in both woodland and grassland than in fields, with this trend being most pronounced for predatory and large species. To conserve high levels of gamma diversity, it is important to maintain a mosaic of agricultural areas and semi-natural habitats. The latter also form a potential source for predatory species important in pest control. It appears that woodland-specific species are rare in the study area, or they have not been able to reach and colonize the newly established woodland sites. It can also be concluded that morphological and ecological traits allow important insights into underlying ecological principles of overall diversity patterns.