Toxicity identification and quantification are important factors to evaluate the effect of industrial effluent on the aquatic environment. In order to measure the potential and real toxicity of mixed chemicals in the effluents, the biological method (i.e., WET test) should be used as well as chemical analysis method. In this study, we conducted WET test for various kinds of industrial effluents using aquatic organisms such as water flea (Daphnia magna), algae (Pseudokirchneriella subcapitata), fish (Oryzias latipes, Danio rerio), and microorganism (Vibrio fisheri). In addition, we carried out chemical analysis and TIE (Toxicity Identification Evaluation) for effluents in order to identify the substances causing toxicity. Among the 30 kinds of wastewater, S13 showed the highest eco-toxicity and $Ca^{2+}$ and $Cl^-$ ion were suspected as major compounds causing toxicity for aquatic organisms. In order to confirm these suspected compounds, various confirmation procedures need to be carried out.