The objective of this research was to determine: 1) the individual toxicity of cadmium and chromium on E. fetida on protein content; 2) the combined toxicity of cadmium and cadmium on E. fetida in lou soil. In individual toxicity, the increased heavy metal concentration can decrease the protein content (P<0.01); the protein content increased as the time goes by (P<0.05). Different concentrations of Cd were the main factors influencing in individual Cd toxicity. Time was the main factor influencing in individual Cr toxicity. Combination of metals, no obvious regulations of time toxicological effects were identified, and the protein contents were significantly affected by Cd concentrations.