The aim of this paper is to deepen research on the possibility to improve the performance of low quality pellets by adding wood biomass. The biomass pellets derived from mixtures of wheat straw and wood of acacia and energetic willow served as object of research. In order to achieve the intended purpose, a number of objectives have been established, among them: establishing the possibility to improve the quality of pellets derived from wheat straw by adding wood biomass of acacia and energetic willow, estimating the calorific value and ash content of the pellets with different percentage of straw and wood biomass and comparing these indicators with the requirements established by ENplus. The researches were conducted in the Laboratory of Solid Biofuels of the State Agrarian University of Moldova using standard methods for estimating physical and mechanical properties of the lignocellulosic biomass.