The hydroponic experiments which included cadmium stress, the observation experiment of ryegrass seed germination and root growth with the combined effects of nano carbon black and cadmium. The determination of cadmium content in three weeks ryegrass seed seedling by applying inductively coupled plasma mass spectrometry (ICP-MS) were carried out to study the impact of cadmium on the germination of ryegrass seed and seedling growth, as well as the recovery effect of nano carbon black on cadmium pollution. The results indicated that the promotion effect of cadmium on ryegrass seed germination rate and germination index is lower with the increasing concentration of cadmium. The concentration of cadmium appears to have typical Hormesis effect on seedling root elongation shoot length and the index of seed vigor. The promotion effect is the most obvious when the concentration of cadmium solution is 5mg/L. The ryegrass seed germination capacity promoted obviously with relatively low cadmium concentration (10mg/L) by adding a fixed amount of nano carbon black. At the same time, the germination rate of other seeds is higher than other treatment groups without nano carbon black. The results of ICP-MS showed that the cadmium content in seed increase as the cadmium concentration is higher. When concentration of cadmium solution is less than 100mg/L, the treatment group with nano black carbon has lower content of cadmium than other treatment groups without cadmium, which means that the nano carbon black has inactivation effect on cadmium and it can reduce the cadmium content in seedling by inhibit seedling to absorb cadmium.