Entre Ríos province is an important center of Eucalyptus spp. plantations in Argentina. It was hypothesized that fine root biomass and litter mass increased with age increasing in plantations. Five, seven and seventeen year old stands of Eucalyptus grandis were sampled. All of them were first rotation stands. We estimated the mass of litter and fine roots (< 5 mm) in the top 30 cm of the soil profile. We determined: carbon, nitrogen, phosphorus, potassium, calcium and magnesium concentrations in living fine roots and litter. Their mineral content was calculated. ANOVA was used for comparisons among stands. Biomass and mineral content of fine roots in the 30 cm of the soil profile were similar in seven and seventeen year old stands and higher than in the five year old stand. When only 10 cm of the soil profile were considered, the seventeen year old stand exhibited the highest biomass and root mineral content. Before seven years fine root biomass and mineral content were stabilized. Mass and mineral content of the litter increased with age. Redistribution of roots in the soil profile with stands age might be related to the increased litter stock and its influence on water and nutrient dynamics.