Ar experiment concerning a clonal test of E. urophylla*grandis was carried out in Congo and presented the following results. The study of variation along the stem showed that basic density decreased sharply from the base to 1.3 m and then increased as the sampling height increased. Consequently, the best prediction of the mean tree basic density was obtained with disks taken at 25 or 50% of the commercial height. A different result was obtained for the mean tree bark percentage which was correctly predicted with 3 samples. Genetic analysis indicated a higher heritability for basic density and low genetic correlations with volume, confirming results obtained from breeding populations of E. urophylla*grandis. Results relating to the method of sampling and selection strategy are discussed in this paper.