The chronic toxicity of four kinds of phonetic compounds to daphnia mugua straus was determined . the relationship of the structure and effect of the compounds were discussed by the chronic results . the results show that all the compounds we measured have effects on the reproduction of the daphnia magua straus 烷基酚化合物对四种水生生物的毒性机制主要与脂水分配系数相关，为通透生物膜产生毒性的非反应性毒性，而氯代酚对四种水生生物的毒性机制一方面和logp有关的，另一方面是和电子效应相关的反应性毒性。
