Woody species diversity in Kelardasht region, North of Iran was studied in a mixed Picea abies and pinus nigra plantation and a mixed broad-leaved coppice stand. For this purpose by using systematic- random sampling method with circular plots of 100m² in 20×50 grid lines were inventoried. Species and number of woody plants (tree and shrub) were recorded in plots. Plant diversity, richness and evenness were determined using the Simpson, Menhinic and Peat Indices respectively. The result shows that the most frequent native trees were found in broad-leaved coppice stand. Broad-leaved coppice stand had higher diversity than coniferous stand but lower richness and evenness.