In this study, the potential applicability of the modified Shuisheng-4 culture medium with Na2CO3 buffer for CO2(g), capture and the resultant CO2-rich solution was investigated for the autotrophic growth of Nannochloris sp. Na2CO3 solution after absorbing CO2(g) controlled at pH similar to 7-8 contains high dissolved inorganic carbon (DIC=HCO3- +CO2(aq)) concentration in water applicable to both open and closed systems and the pH is suitable for the growth. High DIC concentration was also found to enhance the autotrophic growth rate when the Na+ concentration is similar to <120 mM. However, the tolerance of a marine green alga, Nannochloris sp., to Na+ ion was found to be twice as much as that of a freshwater green alga, Chlorella vulgaris. Therefore, it is anticipated that Na2CO3 buffer solution has potential for better CO2 utilization for the mutual benefit of microalgae-derived biomass production and carbon recycle. (C) 2016 Elsevier Ltd. All rights reserved.