Abstract: The physico-chemical and biological toxicity in indices of the wastewater in 4 typical industries in Liaoning were monitored and assessed. The results indicated that both COD and SS concentration exceed greatly the prescribed standards for environmental protection in the effluent from paper-making and metallurgy industries, whereas mainly the COD exceeds the standard in the effluent from chemical industry. The relative opacity of luminescent bacteria showed that the grades of aquatic toxicity of the effluents from paper-making, petroleum/coking and metallurgy industries are high and most of them are between fatal and medium. But the biotoxicity grade of the effluent from chemical industry is in the low-medium range. It was found that there is a highly obvious correlation between COD/SS concentration and various biotoxicity indices in the effluent from paper-making industry, while that between volatile phenol and various biotoxicity indices is proper in the effluents from petroleum/coking and chemical industries. As to the effluent from metallurgy industry, the correlation between COD and biotoxicity indices is also proper.