Abstract: The effect of different carbon sources on growth of Frankia isolates for Casuarina sp.was studied. For each of the three isolates,JCT287,KB5 and HFPCI3,growth was greatest on the carbon sources pyruvate;for the low carbon concentration growth was generally better than that at high carbon concentration. In addition,three cultural methods for Frankia were compared,the results showed that culture with air supplied and fermentation can increase growth of Frankia. The conditions of ferment were discussed.