With the rapid development of secondary fiber industry, more and more attention to the pollution discharge from its effluents and sludge were caused. The toxicity studies on coated white board effluents of secondary fiber were carried out by using optimized photo bacteria method. The results showed that the value of EC50 for acute toxicity in coated white board effluents, which were produced from liners effluents and compositive effluents, were 85.50% and 89.77% respectively, reached the level of Moderately Toxic, by contraries from barrier coating effluents, was 157.57%, belong to Non-Toxic Class. As far as a total organic load is concerned, the value were 63.120 kgCODcr/t-paper, and the total TEF were 33.42 TU·m3/t-paper approximately, as well as equivalently 3.342g HgCl2/t-paper. Therefore, it should be pay more attention to the toxicity and toxicity emission load of coated white board effluents.