Palm kernel shell, Elaeis Guineensis-tree shell silvers, coconut-tree bark and timber-origin biomass samples were studied for biodegradability by std. detn. of chem. O-2 demand (respirometty) and by dissoln. in H2SO4/H2O2 mixt. Microcryst cellulose was used for comparison. The studied biomass samples (except for palm kernel shells) showed satisfying biodegradability (32-45% after 28 days) and can be recommended as solid biofuels for power generation. The selective dissoln. method gave higher biodegradability values than the respirometry.