Resumo. This work aimed to evaluate the effect of inversion of Prosopis juliflora and Leucaena leucocephala fence posts, in distribution, penetration and retention of copper chrome borate (CCB) solution applied by sap displacement method. The Prosopis juliflora was collected in Brazilian Agricultural Research Company (EMBRAPA) and the Leucaena leucocephala at the Federal University of Campina Grande in Patos, Paraíba state, Brazil. Trees with DAP from 5.0 to 10.0 cm were employed. Disks of 2.0 cm of thickness were retired on the top and on the base of pieces. The external disks were then discarded and the intern ones were employed to determine the wood characteristics, being the round pieces with 2.0 m. A solution of 2% of active ingredients of CCB was used to treated woods. A total of 10 pieces of each species were treated, and five of them remained in the solution for 8 days and the five ones had their tops inverted after the sixth day of treatment. The pieces were seasoned; disks of 2.0 cm of thickness were taken in 5 positions along of pieces and the analyses for determination of copper and boron penetration took place. The values of wood characteristics indicated that the pieces were homogeneous. The absorption of the solution was of 19.9 liters ( Prosopis juliflora ) and of 17.0 liters ( Leucaena leucocephala ). The nominal retentions of CCB were 7.72 and 5.34 kg active ingredients (a.i.)/m 3 , respectively. In general, the inversion of the pieces in the preservative solution is recommended, by providing a better distribution, penetration and retention of CCB on treated pieces.