Abstarct: Sempervivum is an evergreen plant with rosette-shaped fleshy leaves belonging to Crassulaceae family. Its various species have medicinal, edible and ornamental value. In this study, morphological diversity, antioxidant activity, content of phenolic and flavonoid compounds, and some secondary mextabolites of Semprevivum plants in two area of Abr forest in Semnan province were investigated. To eliminate the effect of environmental factors on the morphological characteristics of the plants, they were potted and cultivated in a greenhouse in Shahrood for one year. The data of vegetative and reproductive traits including 69 traits were recorded and evaluated according on the descxriptor of the Sempervivum at the beginning of the growing season in April and July. The results showed that there was the least diversity among the collected plants. Among the traits, the highest variation was observed in the color of the crown leaf tip and the least in the color of the crown leaf. Positive and negative correlations were observed between some traits. The study of flower characteristics and vegetative traits led to the identification of only one species of Sempervivum called Sempervivum iranicum in both areas of Abr forest. One plant from the identified species was randomly selected and evalution of methanolic leaf extract using HPLC with 9 standards including vanillic acid, caffeic acid, hesperidin, naringin, gallic acid, coumarin, fluoric acid, quercetin, and berberine Showed that these secondary mextabolites may not be detectable in this plant. Antioxidant activity of the extract using DPPH free radical scavenging methods, nitric oxide trapping, evaluation of iron regenerative power, and chelating agents showed that this plant has high antioxidant activity. Measurement of the phenol and total flavonoid content by Folin-Ciocalteau assay and colorimetric methods, respectively showed that the antioxidant properties of this plant can be due to the presence of 45.09 ± 3.96 mg GAE/g sample phenol and 32.03 ± 0.03 mg QUE/g sample flavonoid. It seems that this plant can be a good candidate for consumption in the food and pharmaceutical industries, but to achieve this, more research is needed.