An insulated fiberfill comprises a first fiber layer and a second fiber layer. The first fiber layer comprises an inner surface and multiple connecting portions arranged on the inner surface and spaced from each other. The second fiber layer is mounted on the inner surface, and comprises multiple joining portions respectively connected with the connecting portions and multiple folding portions inclined toward a same direction. Each of the folding portions is formed between two adjacent joining portions, leans against an adjacent folding portion, and covers at least one of the joining portions. Accordingly, the insulated fiberfill is beneficial for enhancing the capability of the coat and sleeping bag to keep the human body warm. Also, the fabricating steps of the coat and sleeping bag are simplified, and the fabricating time of the same is shortened.