[PROBLEMS] To provide a preventive means or a therapeutic means efficacious against liver fibrosis and to provide a liver fibrosis inhibitor, a medicinal composition, a food and a drink usable as the therapeutic means. [MEANS FOR SOLVING PROBLEMS] It is intended to provide a liver fibrosis inhibitor which contains a shiitake mushroom mycelium extract or a fraction thereof. It is also intended to provide a liver protecting agent having an effect of inhibiting liver fibrosis which contains a shiitake mushroom mycelium extract or a fraction thereof. It is also intended to provide a medicinal composition, a food, a drink and so on containing the above-described fraction.
