The incubating period,hatching period,hatching rate of fertilized egg,deformation rate,larvae survival rate within a certain period of time(24 h and 48 h)and survival activity index(SAI)of newly hatched larvae of Lethrinus nebulosus were observed at salinities of 0,5‰,10‰,15‰,20‰,25‰,30‰,35‰,40‰ and 45‰,and pH values of 5.5,6.0,6.5,7.0,7.5,8.0,8.5,9.0,9.5.The results showed that the incubating period and hatching period of L.nebulosus demonstrated a variation tendency of shortening first and then lengthening within a certain range of salinity and pH values;hatching rate and larvae survival rate within a certain period of time(24 h and 48 h)became higher in salinity from 10‰ to 45‰;hatching rate and larvae survival rate within a certain period of time(24 h and 48 h)became higher in pH values from 6.5 to 9.0.The SAI of newly hatched larvae of L.nebulosus became higher in salinity from 10‰ to 40‰;the SAI of newly hatched larvae of L.nebulosus became higher in pH values from 6.0 to 9.0;larvae only SAI values higher than 3 could be reared to finish their metamorphosis and become young fish.The others would die in several days.Taken together,results showed that:Salinity from 10‰ to 45‰,pH from 6.5 to 9.0 are suitable for hatching and the optimum is salinity from 15‰ to 40‰,pH from 7.0 to 8.5,respectively;Salinity from 10‰ to 40‰,pH from 5.5 to 9.5 are suitable for larvae survival and the optimum is from 20‰ to 25‰ for salinity,and from 7.0 to 8.5 for pH,respectively.