To provide a composition and method capable of safely masking bitterness in medicines, quasi-drugs or foods and drinks.SOLUTION : A bitterness masking composition contains welan gum and/or native gellan gum. A bitterness masking composition further contains a high intensity sweetener. A bitterness masking composition contains xanthan gum and a high intensity sweetener. The bitterness masking composition preferably has a viscosity of 50-1, 500 mPas. A bitterness masking method includes a step of bringing welan gum and/or native gellan gum into contact with a bitterness component, a medicine, a quasi-drug, or food and drink containing the bitterness component. A bitterness masking method includes a step of bringing xanthan gum and a high intensity sweetener into contact with a bitterness component, a medicine, a quasi-drug, or food and drink containing the bitterness component.SELECTED DRAWING : None