RESUMO ABSTRACTModelos hipsométricos e volumétricos são ferramentas úteis para monitorar o desenvolvimento de plantios de restauração florestal. Neste estudo, foram ajustadas equações de estimativa de altura total (h) e volume total com casca (v) em função do diâmetro à altura do peito. Height-diameter and volume models are useful tools for monitoring the development of forest restoration stands. In this study, equations of total height (h) and total volume with bark (v) were fitted as a function of the diameter at the breast height. The data were collected in 20 trees measured and scaled in mixed young forest stands of restoration located in the municipalities of Itapoã do Oeste and Cujubim, North of Rondônia State, in which five heightdiameter and volume regression models were tested. Also, the use of a mean form factor for volume estimation was examined. The models were judged by the coefficient of determination (R²), standard error of the estimate in percentage (Syx%) and graphic residual analysis. All the tested height-diameter models presented satisfactory results, with Syx% of 15%, R² between 0.5443 and 0.5946, being Henriksen's model was the best. The volume models presented Syx values of 11%, R² between 0.8497 and 0.9117, therefore, precise. The best volume model was the Kopezky & Gehrardt. It was concluded that there is a strong correlation between the mensuration variables (between 0.7573 e 0.9531), that the form factor is not accurate to estimate volume. In addition, the regression models, both height-diameter and volume, are accurate and can provide reliable estimates for monitoring young restoration stands in Amazon.PALAVRAS-CHAVE: Cubagem, Plantios jovens, Quantificação volumétrica.