Fulvic acid extracted from Motoyama-, Hara-, and Iga-kibushi clays was subjected to elementary and spectroscopic analysis. The functional groups involved in the fulvic acid were also analyzed by the nonaqueous titration method. In comparison with the humic acid, the character of fulvic acid was verified as follows:
1) Fulvic acid was more abundant in oxygen and less in carbon than humic acid.
2) There was not much difference in the functional groups and also in their amount between fulvic acid and humic acid.
3) The amount of functional groups was smaller in humic substances involved in kibushi-clay than in that in soils.
4) Because of the weak intensity for C=C stretching vibration of aromatic ring, the degree of condensation was considered to be low for fulvic acid.