This paper was the results of experimental studies on the physical properties related to moisture absorptions, rates of breaking tensile and compressive strength, frictional coefficients and angles of repose of the woody pellets, and the inflammabilities releted to calolific values and temperatures of catching flame of the woody pellets as fuel on heating for a horticultural plant. And the woody pellets were made of the mixed sawdusts and barks, chaffs, straws of rice, bagasses and pulp sludges respectively.
The main results were as follows ;
1) The compressive strength of woody pellets was comparedadvantegeously with the tensile strength of these, because the compressive breaking stress ranged the values of 25～190kg/<cm>^^^2, and the tensile breaking stress ranged the values of 1.0～7.6kg/<cm>^^^2.
2) The differences of frictional coefficient among the woody pellets werea little, and the angles of repose ranged 25～31 degrees with respect to all woody pellets.
3) The differences of moisture absorption among the woody pellets were a little but the incremental percentage of moisture content of these during sixty hours was not exceeding about 1%.
4) The differences of the rate of breaking amonh the woody pellets due to the dropping test were a little, but the woody pellets of the mixed sawdusts and barks were made easy break.
5) Total calolific values of woody pellets ranged 30000～50000kcal/kg, although the values of these led slightly the different values among the woody pellets.
6) The temperature of catching flame was remarkerbly dcreased with increasing of the temperature of the atomosphere of the heating unit. And it showed not exceeding the value of 10～20 sec when the temperature of the atomosphere of the heating unit rose more than about 700℃.