Abstract: The influence of brominated flame retardants on the bio-leaching of copper from waste computer motherboards by Thiobacillus ferrooxidans was studied. After the powder with mesh size 0.84-2.00 mm was collected, different kinds of samples were added into the solution to obtain four series with the raw waste computer motherboards:untreated waste computer motherboards, treated waste computer motherboards, treated waste computer motherboards and extractant, and the control group (without waste computer motherboards). Solid-liquid extraction with CCl₄ as the extractant was employed to remove the brominated substances on the waste computer motherboards. After each time interval, Fe ions and Cu ions were sampled and determined. ORP(E_h) and pH were also recorded. The results showed that the leaching efficiency of copper from the raw waste computer motherboards, the treated ones and the extractant groups were different during leaching. The treatment group had the best performance, while the extractant one had the worst. The content of Fe ions and the values of E_h and pH showed a relationship with microbial activity and the content of Cu ions during the leaching process. The larger the microbial activity was, the greater the content of Cu ions and the value of pH were, while the trend of the other two indexes were opposite. Otherwise, the content of Cu ions and values of pH were small, while the content of Fe ions and the value of E_h were large. After leaching for 24 hours, as compared with the untreated group, the Cu leaching efficiency of the treated group was 14.11% higher, while the efficiency of the extractant treated group was lower by 27.69%. After leaching for 168 hours, as compared with the untreated group, the Cu leaching efficiency of the treated group was 17.37% higher, while the efficiency of the extractant treated group was lower by 21.67%. The experimental results showed that the use of brominated flame retardants on waste computer motherboards was one of the important factors affecting copper leaching efficiency. In order to further improve the copper leaching efficiency, we must consider the effect of the brominated flame retardants on the growth of microorganisms.