Aims: Our objectives were to reveal the role of activated carbon in protecting the roots of wheat (Triticum aestivum L.) seedlings under Cd (cadmium) stress. Methods: The roots of wheat seedlings were subjected to hydroponic conditions, and the length, dry weight, fresh weight, level of cell death, and soluble protein content of the roots were measured and compared under Cd stress in the presence of activated carbon. Important findings: Under Cd stress, the length, dry weight, and fresh weight of the roots of wheat seedling significantly decreased, while the level of cell death and content of soluble proteins of the roots significantly increased. These observations indicate that Cd stress causes obvious damages to the roots of wheat seedlings. Sole application of activated carbon had no negative effects on the length, dry weight, fresh weight, level of cell death, and content of soluble proteins of the roots of wheat seedlings. In addition, the application of activated carbon enhanced the growth of the roots and decreased the level of cell death of the roots to some extent. Further, the values of the length, dry weight, fresh weight, level of cell death, and content of soluble proteins of the roots under Cd stress were compared with those under Cd stress in the presence of activated carbon. The results revealed that the values of the length, dry weight, and fresh weight of the roots under Cd stress were significantly lower than those under Cd stress in the presence of activated carbon, while the level of cell death and content of soluble proteins of the roots under Cd stress were significantly higher than those under Cd stress in the presence of activated carbon. These results indicate that application of activated carbon can protect the roots of wheat seedlings against Cd stress.