Carbon dots (CDs) profiting from their stable photoluminescence, small size and good biocompatibility have been used in higher organic fields. The relationship between CDs and edible fungi was less reported. Herein, blue emission CDs are prepared by one-step hydrothermal synthesis, and applied on oyster mushroom (Pleurotus ostreatus) for studying the relationship between CDs and mushroom. Laser scanning confocal imaging shows that the CDs could enter into mushroom hypha. The CDs also can transport among the sporophore. The CDs could be nutrition for oyster mushroom hypha growth in PDA-free medium, and the enhancement effect of CDs on edible fungi hypha is dose-response. Using high concentration on sporophore, their growth would not be affected. It shows that the sporophore of oyster mushroom has well toxicity tolerance for CDs. This study illustrates the relationship of uptake, translocation and toxicity of CDs on edible fungi, which lays the foundation for CDs further application on edible fungi system.