The paper proposes itself to present some aspects about woody biomass as renewable source of energy and about one of the main product namely wooden briquettes. There will be put the accent on physical features of wooden briquettes namely its density but there has be not forgotten the ecological influences. It is also stated the conditions of experimental, type of machine that is used in laboratory experiments, type and feature of raw material and wooden briquettes. Finally some conditions for a good combustion are expressed taking into account ecological and energetically consideration.