Caucasian alder is one of the fast growing and native species planted extensively over the last decades in the north of Iran. In this investigation quantitative and qualitative characteristics of Caucasian alder was studied in the 19-years old pure plantation with an area about 10 ha (row spacing: 2×2 m), in Siahkal region (Guilan province). In this research random-systematic sampling method was used. The area of each sample plot was 400 m² (20×20 m). Diameter at breast height (DBH), tree total height (TTH), crown height (CH), stem quality (SQ) and crown vitality (CV) were measured for all trees. The results showed that average density of trees was 2105 stem per ha and viability was 84.5%. Arithmetical mean of DBH, TT and CH were 13.11 cm, 13.8 m and 5.3 m for Caucasian alder, respectively. The mean annual diameter and height increment of trees were 0.66 and 71.54 cm, respectively. The mean standing volume and mean annual volume increment were 251.49 and 13.23 m³ per ha, respectively. Also the results showed that, from the viewpoint of SQ, 34.6%, 45% and 20.4% of trees were first, second and third classes, respectively. In light of CV 61/3%, 22.5% and 16.2% of trees were first, second and third classes, respectively. In general our findings showed that the amount of annual growth of alder trees in comparison with similar plantation is low, because silvicultural practices, specially thinning operations were not carried out in the studied plantation.