Abstract: To explore the effects of continuous salt stress on the growth of four strains of desert Chlorellas TLD2A1, TLD6B, GTD7c-2 and TGD8A1 under different salt stress levels, the parameters of OD680, lethality, biomass, and specific growth rate of four strains of desert Chlorella were performed under different NaCl addition and different stress time.Chlorella with significant response to sustained salt stress was selected, and the gradient of NaCl addition was optimized. The results showed that, except for the increase in biomass under salt stress with the addition of 0.2 mol/L NaCl, the inhibition degree of OD680 value, biomass, and specific growth rate of the four Chlorella strains gradually increased and the lethal rate gradually increased as the increase of NaCl addition.With the extension of stress time, OD680 value, lethality and biomass gradually increased, and the specific growth rate first increased and then decreased.In general, GTD7c-2 was salt-tolerant, GTD8A1 grew unstable after salt stress, TLD2A1 was the least salt-tolerant, and TLD6B responsed most significantly to salt stress.

Key words: desert Chlorella, sustained salt stress, growth, influence, comparison