This article aims to quantitatively evaluate the biodiversity of medicinal plants in order to protect vulnerable species. Biodiversity has been involved in a crisis rooted in human activities since past. In lack of control over unlimited human expectations, the destructive effects on  environment will increase and the crisis will exacerbate. Iran has a variety of ecological regions where have created animal and plant biodiversity and also a variety of climates, ethnics, cultures, customs and rituals.The present study is based on field studies in the rural areas of Darab city of Fars province: Morvarid, Hyderabad, Dehmord, Fath al-Mubin. Based on the findings, 89 species of medicinal plants belonging to 43 families are identified in the target areas. The largest number with 14 species belongs to the mint family. This area has 6 biological type, 4 vegetative forms, 8 consuming organs with 3 germination periods that are distributed on both even and steep surfaces. According to the results, 9 plants are seriously exposed to damage: Ferula Assa-foetida, Pistacia Atlantica, Zataria Multiflora, Amygdalus Scoparia Spach, Ziziphus Spina Christi, Prangos Ferulacea, Dracocephalum, Myrtus Communis, Ziziphora Clinopodioides. High interest in the use and exploitation of medicinal plants, failure to record indigenous knowledge and lack of revitalization, development, conservation and supervision, will probably lead to deletion of effective plant genes of this region in the near future.