Cyanobacteria are autotrophic prokaryotes performing oxygenic photosynthesis,and their photosynthetic activity is restricted by various environmental factors.We investigated the effects of temperature,pH and light intensity on the growth of transgenic Anabaena sp.strain PCC 7120 harboring hGM-CSF gene in this research.The results showed that the optimal temperature,pH and light intensity for the growth of transgenic cells were about 30℃,9.5 and 90 μmol·m-2·s-1,respectively.The changes in photosynthetic activity while transgenic cells were supplemented with carbon or nitrogen source,showed that the photosynthetic activity of transgenic cells was enhanced by adding both inorganic and organic sources.The transgenic cells of Anabaena sp.strain PCC 7120 was optimal to grow in BG-11 medium containing 10 mmol·L-1 NaHCO_3 or 5 g·L-1 glucose.By contrast,the photosynthetic activity of transgenic cells was inhibited by adding nitrogen source.