Provided is a composition with inhibiting fat formation and antioxidative activities. The composition comprises an effective dose of a Rhodiola rosea extract and a glycerolphosphocholin and a pharmaceutically acceptable carrier or a pharmaceutically acceptable salt thereof. Animal experiments have confirmed that by mixing the Rhodiola rosea extract with the glycerolphosphocholin, the body fat in animals can be effectively reduced and the antioxidative effect can be improved.