Corticolous mosses are one of the most important components of biodiversity in forest ecosystems but unfortunately there is no sufficient information about their role in forest ecology because these are not known as prominent components of the forest ecosystems. In the current research, we identified mosses species which were distributed on bark of Caucasian Walnut. Also we surveyed the correlation of biodiversity index with some bark physic-chemical characterizations. Fifteen individual trees were selected in Noor forest park-Mazandran and the data was collected in a sampling quadrat with 30×40 cm dimension on their bark. The bark samples were collected from the north and south aspects and transferred to laboratory for measuring of pH, electrical conductivity and water holding capacity. After taxonomic study, 11 moss species were identified that Palamacladium euchlora were found on more than 93% of all individuals. Among all of 11 species, Hypnaceae family with three species had the most numbers. There was no significant difference in pH between north and south aspect, although water holding capacity was higher and electrical conductivity was lower in north aspect in comparison with south aspect. Biodiversity indexes such as species diversity, species richness and evenness didn’t have significant correlation with bark physic-chemical characterizations. It seems that bark morphological and physical traits provided a suitable condition for the corticolous mosses. The correlation of bark thickness and track size with biodiversity index can be considered in the future researches.