Abstract: Effects of fire on vegetation are usually the most obvious impacts of burning. Iran has a total of 1.2 million ha temperate forest in the north where fires occur in ca. 300-400 ha annually. These are mostly surface fire and affect mainly undergrowth and young trees. This study focuses on the impact of fire on herbal layer biodiversity in Chelir forest in north of Iran. Biodiversity indices and coverage percent were used for comparing herb`s species between burned and unburned area. Biodiversity indices and coverage percent of shade tolerant species in unburned area were higher than burned area. It is necessary to consider recruitment practices such sowing and planting to prevent biodiversity decreasing and promote ecosystem stability.