Intraincremental wood density determination by means of X - ray radiation of samples, using a direct method of measurement with one proportional counter, is described and analyzed. The resolution power attained proved appropriate in determining intraincremental wood density variability. Results obtained from the stem analysis of one tree are discussed and some preliminary relationships between density and other characteristics such as cronological age, physiological age, early wood, transsition wood, and late wood are included.