Arbuscular mycorrhizal (AM) fungi help in enhanced uptake and transport of poorly mobile soil-nutrients improve water-relations and reduced pathogenic infections of deleterious soil borne fungi and other microorganisms. Biodiversity of arbuscular mycorrhizal (AM) fungi in different forest tree species growing in natural forests, plantations, agroforestry systems in different parts of Bangladesh and tree seedlings from different nurseries was carried out in this research. Mycorrhizal dependency and responsiveness were conducted to study the effect of inoculation of AM fungi in plantations and nursery seedlings. Authors are grateful to the Department of Botany and Institute of Forestry and Environmental Sciences, University of Chittagong (IFESCU), Bangladesh. They are also thankful to the students of Dept. of Botany and IFESCU. Special thanks to different research institutes, farmers, nursery care takers, and field workers in different forest offices for helping during this research program.