The Human Figure Drawing Test (HFD Good-enough & Harris, 1926) is a psychometric scale developed to measure individual evolution of conceptual maturity in children of school age. This concept is described as the ability to develop concepts with an increasing degree of abstraction (Harris, 1963). In despite of being a widely applied test in professional contexts, its psychometric properties were not properly analyzed in local populations. This paper proposes an advance on its metrical adaptation, in order to be used in scholars from Buenos Aires and its suburbs. To reach this research goal, item homogeneity and difficulty indexes were calculated. Following original Koppitz's proposals (1968), expected develop mental items were identified, as well as the common and exceptional ones in each age interval considered. Discriminate validity evidences regarded to Bender's Gestalt Scale were also analyzed. Considering children's age, common parts composing the human figure were identified, meaning that 85% per cent (and more) of the children in a given age included that part as an important detail in the drawing. This way, it became an expectable item for that age interval. Unusual elements were also identified (15% of the cases or less) in protocols of each analyzed group. This analysis showed that some parts were omitted for the majority of children in the studied sample. The applied utility of this particular analysis consists in the identification of items which would be present in drawings produced by children with out problems in each age level in local population, when a normative criterion is follow ed in the individual assessment. The importance of an item omission when it is expected must be highlighted, because of its importance as a relevant indicator of potential problems. The contribution here in tended consists in the description of this maturational ability using parts of the drawing which become expectable in a given develop mental age. The absence of certain details may imply conceptual immaturity; these two kinds of indicators are characterized in the differential diagnosis and are key signs in applied assessment situations. Concerning discriminate validity evidences, a significant average and positive association be tween scores of conceptual maturity (HDF) and visual-motor ability (Bender's) was verified in the whole simple. Associations became lower if the simple was spitted by age. Developmental motorist and perceptual aspects appear to converge with conceptual abilities measured in the sample, existing an overlapping of both of them in the activities involved, although not lower enough to speak about abilities related but about abilities of a different nature. Despite both scales (HFD and Bender's) demand a graphic action to be responded, they intend to assess theoretical concepts hypothetically differentiated. Otherwise, empirical verifications seem to speak about a significant relationship between them. Analyzing the association between these abilities through an increasing curve of age during childhood allows to infer a decrease in values of Pearson coefficients as chronological age increases (.259*; .234**; .474**, .179*, .283**, .189*, and .251). Such results can be interpreted as a gradual discrimination between perceptual, motorist and conceptual abilities, when developmental level shows an ascendant peak. One of the limitations of this research lies in the sample employed, which involved a restricted number of participants across each age included. Future developments must improve this issue, in order to challenge these findings. For this reason these results must be analyzed as preliminary tendencies. Their potential intention of generalization should be tested in future studies, and also by means of the generation of new research lines. These advances are disposable to be tested in new populations, and they intent to become a contribution for applied practice of psychological assessment with children. [ABSTRACT FROM AUTHOR]