Abstract: The growth rate, photosynthesis and chlorophyll fluorescence of Nostoc flagelliforme Born.et Flah. cultured under different medium were tested. The results showed that after (11 d) cultivation, the content of chlorophyll a in different medium were (1.08 mg/L) (Detmer), (1.87 mg/L) (Kratz-Myers), 1.21 mg/L (hydrophilous 104), and 2.18 mg/L (BG11), respectively. N.flagelliforme in BG11 had the fastest growth rate. Compared with other concentrations of BG11, the N.flagelliforme cultured in BG11 had the highest gross photosynthesis Pm ((218.1 μmol) O₂·mg^-1(chl a)·h^-1) and the highest ratio of chlorophyll fluorescence (Fv/Fm=0.349). The results indicated that BG11 is optimal to cultivate N.flagelliforme and improves its activities of photosynthesis and chlorophyll fluorescence markedly.