Ricciocarpos natans grows best on Gamborg B5 medium supplemented with 2% sucrose. Six other mineral media were less effective on the growth. During a culture period, pH of the media changed depending on the ammonium and nitrate content of the respective media. In media of a molar ratio of ammonium to nitrate of 1:1 or 1:1.9, pH first dropped from 6.0 to about 3.5 and then rose again. In media where nitrate is the only nitrogen source or where there is a ratio of ammonium to nitrate of 1:12.5, pH rose during the first two weeks and after this dropped. Differences in the light intensity (2000 an d 6000 lx) and light regime (14 h light/ 10 h dark) had no effects on the growth. The cultures produced a variety of terpenoids. The same pattern of compounds was seen in field-collected material as well as in cultivated material. The content of the terpenoids decreased on nitrogen and phosphorous-deficient media.