Abstract: In intensively managed agricultural landscapes, non-cultivated habitats embedded within cultivated land play a crucial role in maintaining herbaceous plant diversity. However, in the black soil region of Northeast China, herbaceous plant diversity and the internal species co-occurrence networks of different non-cultivated habitat types have not yet been systematically characterized. This study aims to quantitatively compare herbaceous plant diversity and species co-occurrence network structures among major non-cultivated habitat types, thereby providing a scientific basis for optimizing the spatial configuration of non-cultivated habitats and conserving herbaceous plant diversity in agricultural landscapes. The study area is located in the Hailun River Basin of Hailun City, Heilongjiang Province. Along the margins of cultivated fields, herbaceous strips were classified according to their habitat characteristics into six non-cultivated habitat types: woodland (WL), grassland (GL), irrigation canals and ditches (CD), paved roads (PR), dirt roads (DR) and village (VL). Herbaceous plant communities within these non-cultivated habitats were comparatively analyzed. In each habitat type, herbaceous plants were surveyed using the quadrat method, and community attributes such as species composition and individual abundance were recorded. For each habitat type, individual abundance and the Shannon-Wiener diversity index were calculated. Differences among habitat types were tested using analysis of variance (ANOVA), while differences in species composition were characterized using non-metric multidimensional scaling (NMDS).Furthermore, species abundance matrices for each habitat type were used to calculate pairwise species associations and to construct herbaceous plant species co-occurrence networks. Key topological metrics, including edge density, average degree and clustering coefficient, were then derived to characterize network structure across habitats and, from a co-occurrence network perspective, to provide indirect insight into the potential stability and resistance of herbaceous plant communities to external disturbances. The results showed that herbaceous plant diversity and species composition differed significantly among non-cultivated habitat types (WL, GL, CD, PR, DR and VL) (P<0.05). (1) Species richness and individual abundance in WL, CD and GL were significantly higher than in VL and DR (P<0.05), with WL exhibiting the highest species richness, abundance and Shannon–Wiener diversity. (2) NMDS ordination revealed clear differences in herbaceous species composition among habitat types: GL, CD and DR supported relatively similar species assemblages, whereas VL differed significantly from the other non-cultivated habitats (P<0.05). (3) Across the six non-cultivated habitat types, herbaceous plant co-occurrence networks were dominated by positive species–species associations, indicating a general tendency toward co-occurrence rather than spatial segregation. Networks in PR, GL and CD were denser, more highly connected and characterized by tighter species linkages, suggesting relatively stable community structure and stronger resistance to disturbance, whereas networks along DR and VL were sparser and more weakly connected, implying lower structural robustness. (4) Within non-cultivated habitats, highly connected co-occurrence networks were characterized by the frequent co-occurrence of herbaceous species from Poaceae and Asteraceae, suggesting that future restoration and management of non-cultivated habitats could prioritize plant assemblages centered on Poaceae- and Asteraceae-dominated herbs to strengthen network connectivity within herbaceous communities, thereby helping to maintain the ecological stability of these habitats and enhance resistance to disturbance.