A water filter assembly includes an upper cover body, a lower base, and a plurality of filter cores. The upper cover body is formed with a connector extending downwards. The connector is to be connected to a filter core set, which includes the filter cores connected together and has output and input hoses. The lower base has a chamber for accommodating the filter core set and has a cover portion connected to the upper cover body. Positioning members are formed on the output and input hoses at suitable positions. Notches are formed on two sides of the cover portion of the lower base so that the positioning members may engage with the notches.