Abstract: A custom-made,carbon-based complex Agent-K was used to purify pig farm wastewater.The purification efficiency was indicated by Misgurnus Anguillicaudatus survival rate,micronuclei rate and nuclear anomalies rate.The results showed that,after treatment,the sewage COD and NH3-N decreased significantly,and the pH and DO values increased significantly.The addition of 6% of Agent-K in a solution containing 50% of the sewage for 5 h yielded the optimal purification result.The chemical indicators of the water had a significant or highly significant correlation with the treatment capacity and time.The M.Anguillicaudatus survival rate increased from 0 to 100% when the Agent-K addition increased from 0 to 8% and treated for 4h.The micronuclei rate and nuclear anomalies rate of M.Anguillicaudatus significantly decreased with increased dosage,as compared to the untreated case.The regression analysis indicated a significant correlation among the purification,survival rate,micronucleus rate and nuclear abnormality rate.They could be used as indicators for effluent toxicity determination.