Ethnobotany consists of the words Ethno and Botany. This science studies the correlation between plants and
people in an area, and provides information about the consumption and application of plants in an area.
Analysis and use of the obtained information play an important role in the development of various fields such
as trade and pharmacy. This research is concerned to study the most widely used plants of Semnan city and
information about their consumption type in this area. In this study, the most widely used plants of Semnan
city were identified using the information of sellers of plant products, personal interview and observation of
plants, and the obtained information was compiled in the form of a questionnaire. In the interviews, the names
of 10 best-selling plants, nature, organs used, how to use and their properties were asked, and then the
scientific name and family name were added for each plant. Interviewees mentioned a total of 70 plants,
which belonged to 36 plant species and 20 families. The families Lamiaceae with 13 species and Apiaceae
with 9 species were the richest families. According to the results, the most used part of plants in this region is
leaves and the most used method is in the form of decoction. Also, the plants mostly are used to treat
digestive problems, treat neurological diseases, strengthen nerves and be sedative. Existence of various herbal
products stores in Semnan city, which are the place of supply of medicinal plants and spices, shows the
attention and interest of its people to medicinal plants. Understanding people’s approach to the use of
medicinal plants can be a good guide for the country’s trade and pharmaceutical industry. We recommend that
research be done in other cities of Semnan province.