Abstract: A storage box includes a base having a bottom portion with inner and outer surfaces, and a peripheral wall surrounding the bottom portion to form a storage space with the inner surface. The outer surface has a placing slot and a knife sharpener fixing portion adjacent thereto. When the user places a knife sharpener in the storage space and closes a covering plate, the whole storage box is portable. The knife is sharpened when the covering plate is detached and embedded in the placing slot while the bottom portion is orientated upward, and the knife sharpener is disposed on the knife sharpener fixing portion. The user moves a knife back and forth between the knife sharpener by one hand and puts the other hand beside the covering plate to avoid being gashed by the knife in the knife sharpening process, thereby achieving protection purpose.