The effects of macronutrients (NO3-, NH4+ and PO43-) on cell growth and triterpenoids production in Centella asiatica cell suspension cultures were analyzed using the Box-Behnken response surface model experimental design. In screening and optimization experiments, PO43- as a single factor significantly influenced cell growth where increasing the phosphate level from 0.1 to 2.4 or 2.6 mM, elevated cell growth from 3.9 to 14-16 g/L. The optimum values predicted from the response surface model are 5.05 mM NH4 +, 15.0 mM NO3- and 2.6 mM PO43-, yielding 16.0 g/L cell dry weight with 99 fitness to the experimental data. While the NH4 +-NO3- interaction influenced cell growth positively in the optimization experiment, NH4 + and NO3- as single factors; and interactions of NO3--PO43-, NH4+-PO43- and NH4+-NO3- were all negative in the screening experiment. Cell growth and the final pH level were positively affected by PO43-, but negatively affected by NH4+ and NH4 +-PO43- interactions. The different effects of factors and their interactions on cell growth and final pH are influenced by a broad or narrow range of macronutrient concentrations. The productions of triterpenoids however were lower than 4 mg/g cell dry weight. © KSBB.