Abstract
Some preliminary studies were performed on the relationships between chemical properties of various soils and the types of their humic acids. The soils were arranged according to humification degree of their humic acids as follows; muck soil>humus-volcanic ash soil>Jagaru(a rendzinalike soil in Okinawa Isle)>alluvial soil>diluvial soil.It was noticed that the types and the amounts of humic acids depended upon not only acidity, calcium cotent, aeration etc. of the soil, but also its geologica1 origin remarkably.
