The biofixation of carbon dioxide (CO2) by marine microalgae cultivation has been regarded as one of the potential to diminish the greenhouse effect and produce the biomass. To compare and select the high efficiency cultivation mode, the effect of two different cultivation modes on the performances of growth and CO2 biofixation from air for energy marine microalgae Chlorella sp. was determined in this work. In one mode the microalga was cultivated using static (open) method and in the other mode it was cultivated using aerated (closed) method. It was found that,. under the experimental conditions, the specific growth rate and CO2 fixation rate of the aerated (closed) cultivation were 0.5121 (d(-1)) and 1.3784g CO2/ld, and are 1.78 and 5.39 times that of the static (open) cultivation, respectively. In addition, the effects of pH value and dissolved oxygen (DO) concentration of the culture medium were analyzed and compared in two cultivation modes. The result indicates the aerated (closed) mode can effectively enhance the performance on microalgal growth and CO2 biofixation. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.