The article includes research related to utilization of waste wood which is primarily size reduced due to its voluminity for next processing for lower value added products for about last twenty years. Procedures and results obtained by different authors were considered in one study. In this review a wood waste downcycling was consider as a process of transformation of large size wood products over their lifetime to the new products, where a size reduction is one of the first operations needed to achieve to. Incineration of each way was excluded from the present review, but second-generation biofuels are considered as potential products for the future. Two points of research selection according to origin and according to products made of waste wood was applied in this review. Comparison shown that the most industrially applicable implementation of treated particles obtained from waste wood is intended to the composite materials production as particleboards, fibreboards, cement-bonded and wood-plastics.