Tea plant contains a lot of polyphenol compounds that act as antioxidants. The addition of milk into tea might reduce the antioxidant activity as milk protein could bind to the polyphenol of tea, thereby decreasing the capacity of polyphenol in reducing free radicals. This study is aimed to determine the effect of skimmed milk to antioxidant activity of white tea and black tea. This study was conducted in a laboratory experimental with 2x3x1 factorial design. Infusion of white tea and black tea was made with content 2 g of tea/ 200 ml of distilled water (g/v). Infusion of tea was then mixed with 1, 1.5 and 2 ml of skimmed milk. The assay of antioxidant activity was done using DPPH method and then analyzed by UVVisible spectrophotometer at λ = 517 nm. Data were analyzed by Oneway Anova and found a significant decrease in antioxidant activity among tea without mixture and tea mix with milk, the value of p = 0.000 (p < 0.05). Independent T-test results showed significant differences in antioxidant activity of white tea and black tea, the value of p = 0.000 (p < 0.05).