The effects of the nitrogen (N) source on the kinetics of cell growth, major nutrient consumption, and production of ginseng saponin and polysaccharide in suspension cultures of Panax ginseng cells were studied. The ratio of NO3-/NH4+ and initial total medium N were altered. Cell growth was better at 60 mM N and higher ratios of NO3-/NH4+. With nitrate alone or a mixture of nitrate and ammonium (at a ratio of 2:1) provided as N source, 10 mM N was found to be a crucial point for the cell mass accumulation. Nitrate was a favorable rv source for ginseng cell growth. A cell growth rate of 0.11 day(-1) and a dry cell density of 13 g l(-1) were obtained at 10 mM nitrate (sole N source). At an initial ammonium concentration above 20 mM, the ginseng cell growth was inhibited, and a higher intracellular nitrate concentration and lower soluble sugar content in cells were observed. The results also indicate that the specific production (i.e., content) of ginseng polysaccharide was not significantly affected by the alteration of N source while the maximum production of polysaccharide of 1.19 g l(-1) was achieved at NO3-/NH4+ of 60:0 under 60 mM of total N (i.e., sole nitrate). The saponin production was relatively higher within initial N concentrations of 5-20 mM (with nitrate alone or a NO3-/NH4+ ratio of 2:1). The highest content (5.2%) and total production (0.6 g l(-1)) of ginseng saponin were obtained at an initial nitrate of 5 mM.