The total forest area of Iran is approximately 12 million ha which make only 7.3% of the total land area. Foundoglu forest is a unique forest with 1773 ha and located at the and of western Elburz Mountain chains, in Ardabil province (North Eastern of Iran). For doing this research, we have organized a sampling to drive structural information of some quantitative and qualitative characteristics. Stand measurement was a systematic random sampling. With the sampling grid of 150x200 m and plot area 500 m2 and the measurement of structural characteristics were done to get information on species, origin of sp., quality of sp., collar diameter, total height canopy cover, regeneration, slope aspect and altitude. Results showed that common hazel is distributed on site between 1370 and 1580 m.a.s.I. with 352.2 mm annul precipitation and mean annul temperature 9.7°C five vegetation types of Corylus-Quercus, Corylus-Fagus, Fagus-Corylus, Corylus-Acer and mixed Corylus were separated.