Abstract: A typical desert filamentous canobacteria, Scytonema javanicum, isolated from desert soil, was selected for research material. Under the laboratory conditions, some environmental factors such as temperatures, salinity, pH and culture time were selected for experimental treatments, and detected the effects of the above environmental factors on the extracellular polysaccharide(EPS) exudation of S. javanicum. The results indicated that with the culture temperature increasing, S.javanicum had higher EPS exudation, and at 35℃ the algae obtained the most EPS production. When salinity was between 0.05 mol/L NaCl to 2.0 mol/L NaCl, the EPS production of S.javanicum increased with the enhancement of salinity.  When the pH of media was maintained at 7.5, there was the highest EPS production for S.javanicum than the EPS production of algal cells under other treatments of pH