Abstract:The compound osmotic stabilizers consisted of several salt solutions exerted a greater effect on the isolation of blue-green algae spheroplasts than a single salt solution. However, the effect of compound osmotic stabilizers on the spheroplast stability could be multiphasic. Some osmotic stabilizers, such as the solution of (NH4) 2C4H406, (NH4) 2SO4 and MgSO4, exerted degradation on cell walls of the blue-green alga; among which the (NH4) 2C4H406 solution (0.15 mol/L) had the greatest degradation resulting in formation of spheroplasts. The spheroplasts were sensitive to hypotonic condition but were less transparent.