To provide a sweetener-containing liquid fermented milk which shows a good balance between sweetness, sourness and so on over a broad liquid temperature range of from 10 degree centigrade or lower to a temperature exceeding room temperature (for example, 80 degree centigrade). A sweetener-containing liquid fermented milk to be taken at a liquid temperature of 20 degree centigrade or higher which contains a high-sweetness sweetener. Examples of the high-sweetness sweetener include sucralose, aspartame, acesulfame potassium, neotame and so on. A method for producing the liquid fermented milk comprises: a fermentation step for adding a lactic acid starter to a starting material of the fermented milk and thus conducting fermentation to give a curd comprising the fermented milk a curd-grinding step for grinding the curd to give a liquid fermented milk and a sweetener-adding step for mixing the liquid fermented milk with the high-sweetness sweetener to give the sweetener-containing liquid fermented milk.