Sparkling wine produced by the Traditional method of bottle fermentation are obtained by biological aging. In the course of this process, phenolic compounds can be released or absorbed by the surface of yeast lees modifying their composition. Aiming to improve the phenolic stability of rosé sparkling wines, the objective of this study was to evaluate the influence of the addition of mannoproteins on the phenolic composition of sparkling wines (cv. Merlot) with different periods of biological aging. Mannoprotein was added to the base wine (0.3 g L-1) before the second bottle fermentation, and a treatment was maintained as control. The samples were analyzed by spectrophotometric techniques (total polyphenols, total monomeric anthocyanins, in vitro antioxidant activity by ABTS method) and high performance liquid chromatography (individual phenolic compounds). The base wine was analyzed before the addition of the mannoprotein and the sparkling wines were monitored for 3, 6 and 12 months of aging. The results demonstrated that the base wines showed high concentrations of the phenolic compounds analyzed. The addition of mannoprotein significantly increased the concentrations of hydroxybenzoic acids in sparkling wines when compared to the control sample during aging. For the hydroxycinnamic acids, it was observed that the sparkling wines with the addition of mannoprotein presented the highest levels of these compounds with 6 (30.9 mg L-1) and 12 months of aging (27.8 mg L-1) in relation to the control. Few effects of the addition of mannoproteins were observed on the total polyphenol content, anthocyanins and antioxidant activity. The addition of mannoprotein significantly increased trans-resveratrol concentrations in the sparkling wines during aging. The use of mannoproteins during vinification as well as during biological aging proved to be important factors that influenced the quality of the sparkling wines, these results suggest the use of mannoproteins to improve stability of phenolic compounds.