The experimental determinations of this research had the aim to select the extraction method and to establish the optimal parameters of obtaining of vegetal extracts enriched with phenolic compounds with high biological activity. As a raw material for research was selected the oak sawdust, a secondary product of wood processing enterprises. The process of extraction from vegetal material has been realized using the statically method (maceration during 24 hours) and the method of extraction in ultrasonic field (during 30 min) of the ratio 1:5 and 1:10 (weight of the dry product/solvent volume). The extraction has been realized at a controlled temperature in 3 steps for each method using as a solvent the ethanol of 50 and 70%. The determination of the total contain of phenolic compounds has been realized by the Folin-Ciocalteu method with minor modifications. The obtained data allows to conclude that for the increasing of the obtaining yield of the bioactive substances from sawdust is to be preferred the use of the extraction method of the vegetal product-solvent in 1:5 ratio in ultrasonic field during 30 minutes, using as a solvent the 50% ethylic alcohol.