The effect of sucrose (0, 10, 20, 30, and 40%) on flow and dynamic rheological properties of xanthan gum (XG) mixed with locust bean gum (LBG) at different mixing ratios (100/0, 75/25, 50/50, and 0/100) were evaluated. The addition of sucrose significantly changed the flow behavior index (n), consistency index (K), storage modulus (G'), and loss modulus (G″) of XG, LBG, and XG-LBG mixtures. When XG and LBG were mixed, there was a synergistic effect on K and G' values, and 50XG/50LBG mixture exhibited stronger synergy than 75XG/25LBG mixtures. However, the addition of sucrose reduced the magnitude of the synergistic effects, indicating that the presence of sucrose in XG-LBG mixtures negatively affected the synergistic interaction between gum molecules. Sucrose may competitively inhibit the binding of gum polymers to water molecules. The rheological properties of XG, LBG, and XG-LBG mixtures were affected by the addition of sucrose in a concentration-dependent manner.