PURPOSE: A soil modifier is provided to prevent the hardening phenomenon of soil by a coking property raw material including bentonite, and to incase the number of aerobic microorganisms in the soil. CONSTITUTION: A soil modifier contains 2-5wt% of carbamide peroxide, 1-10wt% of shell plasticized calcium, 10-20wt% of silicon dioxide,10-30wt% of alumina oxide, 5-15wt% of Iron(III) oxide, 1-5wt% of magnesium oxide, 1-10wt% of kalium oxide, 1-5wt% of sodium oxide, 0.5-1wt% of manganese oxide, 1-3wt% of titanium dioxide, 1-3wt% of phosphorus pentoxide, 0.5-2wt% of germanium, 0.5-2wt% of selenium, and 3-20wt% of oak charcoal powder having the particle size of 1-30 microns.
