This paper attempts to seek out the selecting optimum temperature and avoiding temperature for larva of Liza haematocheila (Temminck et Schlegel) Mullet. Temperatures are regulated by an automatic controlling machine, type of WMZK-01. When the acclimation temperatures are set to 25 o C, 28 o C, 31 o C, the selecting optimum temperatures are 27.2-28.5 o C, 29.0-30.5 o C, 31-32 o C, avoiding temperatures are 34 o C, 35.2 o C, 35.7 o C, respectively. The optimum temperature and avoiding temperature increase with the increase of acclimation temperatures.