Resumo. Red wines are a source of polyphenolic compounds, that contribute to the organoleptic caracteristics and exert beneficial effects on human body, due to its antioxidant actions and inhibitors of platelet aggregation. Our objectives were to determine the concentrations of total polyphenolic compounds, determination of total acidity, pH, sodium and potassium concentration, color intensity and color hue in Merlot wines (Vitis vinifera L), yields from 2004 to 2009, produced in the Midwest region of the state of Santa Catarina. For determination of total polyphenols, we used the Folin-Ciocalteau method; the determination of sodium and potassium was performed according to AOAC (1997), and for other analysis, followed the procedures established by the Adolfo Lutz Institute. Through the analysis, results were obtained from 3.34 g/L to 4.06 g/L of total polyphenols, total acidity from 73.5 to 80.3 meq/L, pH 3.53 to 3.69, sodium concentration of 30.4 mg/L to 84.0 mg/L, potassium concentration of 1.527 mg/L to 1891.8 mg/L, color intensity between 0.59 and 0.99 and color hue ranged from 0.84 to 1.11.