Resumo. ABSTRACT The dynamics was studied in a remnant of an Mixed Ombrophyllous Forest (Araucaria Moist Forest), located in Três Barras National Forest, Três Barras city, Santa Catarina state, in a period of five years (2004-2009). In 2004, it was installed and measured 26 one-hectare permanent plots, subdivided into 10 m x 50 m (500 m²) subplots. All trees with DBH > 10 cm were numbered and evaluated for the taxonomic diversity, the regular annual increment (dbh and basal area), the ingrowth and mortality. In 2009, all plots were measured again to assess changes between the two periods, and the results presented to the entire forest (26 ha) and the 10 most important species. In 2004, the forest had 721 trees/ ha in 2009 passing for 709 trees/ha, distributed in the two occasions in 72 species, 29 families and 53 genus. There was a mean annual increment in diameter (0.27 cm/year), and in basal area (0.28 m²/ha) for the forest as a whole and among the 10 most important species Ilex theezans Mart. ex Reissek and Piptocarpha angustifolia Dusen ex Malme were the species with the lowest (0.08 cm), and highest (0.83 cm), diametric annual increment, respectively. Considering all species present in the study area, the basal area increased by 0.47m²/ha/ year, indicating continued growth to reach their full stock. The average annual mortality rate (AMR) was 2.14% and the annual ingrowth rate (AIR) was 2.01%. Ilex paraguariensis A. St. Hil. had the highest AMR (1.86%/year) and Cupania vernalis Cambess. the highest AIR (2.18%/year). When considering the 10 most important species, Ocotea porosa (Ness) Barroso presented higher annual increment in diameter (0.43 cm/ year) and Araucaria angustifolia (Bertol.) Kuntze with higher basal area increment (0.1874 m²/ha/year). Overall, in the five-year period, the results showed small changes in the dynamics of forest and for the 10 most important species. The small changes are due to the late successional stage of the forest evaluated.