The aim of this study was to determine stand structure and biodiversity of plant species in the Box tree site, Kish khaleh, Talesh. Sampling procedure was the systematic- random method. Type of woody species and their diameter at breast height (DBH, 2 cm) were identified and measured. Also herbaceous species were identified and their numbers recorded within each sampling plot. In addition, number of seedling and sapling of Box tree were recorded. Data analysis was carried out using diversity indices of Simpson, Hill’s N2, Shannon- Wiener, Mc Arthur’s N1 and Wilson and Smith’s evenness index. Species importance value (SIV) was calculated in the woody and herbaceous layers. The results indicated that mean richness of woody and herbaceous species were 13 and 11, respectively. In the woody species layer, mean of richness and the mentioned diversity and evenness indices were 2.613, 0.444, 1.922, 1.029, 2.104 and 0.672, and also in the herbaceous layer the mentioned parameters were 3.310, 0.667, 2.528, 1.394, 2.798 and 0.793, respectively. Structurally, mean of diameter and height of Box tree were 4.87 cm and 5.37 m, respectively, mean basal area equal to 2738.95 cm2, number of Box tree (DBH, 2cm) equal to 4056 per hectare and the number of sapling (H<5 cm) and seedling (DBH<2 cm, H>5 cm) were obtained 44236.11 and 7091.67 per hectare, respectively. In the woody species layer, the highest value of SIV belonged to Buxus hyrcana (221.43 %) and the lowest value belonged to Zelkova carpinifolia (2.84 %), in the herbaceous layer the highest value of SIV belonged to Mentha longifolia (0.68 %) and the lowest value was in Polypodium vulgare (0.11%).