Abstract: Asphyxiation point and lethal temperature for the fingerlings of mullet wereexperimentally dertermined. It was found that the lethal high temperature for thefingerlings of mullet was 36℃ and the range of tolerance may be started from 1℃.While the dissolved oxygen droped to 1.18--0.9mg per liter, the fingerlings comeup to the water surface, and at 0.7--0.93mg pe liter (at 37℃) or 0.52--0 .42mg perliter (at 25--28℃), the fingerlings died in asphyxia.