Seacoast plant communities represent primary successions characterized by a harsh environment in which mycorrhizal symbioses are known to be important for plant survival and growth. The study was carried in two grey dune areas (Užava and Pāvilosta) on the western coast of Latvia by the Baltic Sea. We examined how root colonization and abundance of arbuscular mycorrhiza differed along a primary dune succession from an early successional primary dune to an overgrowing grey dune, in relation to soil factors. We hypothesized that plant species growing on soil with a poorly developed soil horizon and low C, P and N concentration would have a higher extent of arbuscular mycorrhiza colonization. We also tested the relationship of soil factors and fungal abundance in roots within specific plant species. In a total of 93 plots among 5 habitats, we determined soil carbon, phosphorus and nitrogen concentrations and sampled roots of dominant plants for determination of arbuscular mycorrhizal (vesicules and hyphae) frequency, abundance of arbuscular mycorrhizal vesicules and hyphae, and abundance of arbuscules. The results showed that extent of mycorrhizal colonization was related to soil development, being more important in the most nutrient poor habitats, compared to grassland habitats. However, slight increases in P and N concentration were associated in increased mycorrhizal colonization in early successional stages and disturbed habitats.