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Hydraulic anisotropy behavior of unsaturated soil has not been fully investigated. Direct laboratory measurement and indirect determination of hydraulic anisotropy under a drying condition were carried out on statically compacted specimens having different initial conditions. Direct measurement of permeability was carried out using an unsaturated triaxial permeameter whereas indirect determination of permeability was performed through statistical estimation via a measured drying soil-water characteristic curve (SWCC). In this research, two orientations--specifically horizontal-layering (HL) and vertical-layering (VL) orientations--were prepared for a given specimen from statically compacted homogeneous sand-kaolin. The results from both direct measurement and indirect determination of hydraulic anisotropy were in good agreement. Hydraulic anisotropy under an unsaturated condition was found to be similar with that in a saturated condition. Moreover, hydraulic anisotropy was reflected in the ratio of transient time during the direct measurements of HL and VL specimens at high matric suctions. In contrast, in the indirect method, hydraulic anisotropy was reflected in the ratio of equalization time during SWCC tests at matric suctions higher than the air-entry value of the soil. Key words: unsaturated soil, hydraulic anisotropy, permeability, soil-water characteristic curve, laboratory experiment. Le comportement d'anisotropie hydraulique de sol non sature n'a pas ete pleinement examine. La mesure directe de laboratoire et la determination indirecte de l'anisotropie hydraulique sous condition de sechage ont ete effectuees sur des specimens compactes statiquement ayant differentes conditions initiales. La mesure directe de la permeabilite a ete realisee a l'aide du permeametre triaxial non sature alors que la determination indirecte de permeabilite a ete effectuee par l'intermediaire de l'estimation statistique via la mesure de la courbe de caracteristique sol-eau de sechage (SWCC). Dans cette recherche, deux orientations--plus precisement la disposition horizontale (HL) et verticale (VL)--ont ete preparees pour un specimen donne de sable-kaolin homogene compacte. Les resultats a la fois de mesures directes et de la determination indirecte de l'anisotropie hydraulique etaient en bon accord. L'anisotropie hydraulique sous condition insaturee etait similaire a celle de l'etat sature. En outre, l'anisotropie hydraulique a ete refletee dans le rapport de temps transitoire pendant la mesure directe des specimens HL et VL a des hautes succions matrices. D'autre part dans la methode indirecte, l'anisotropie hydraulique a ete refletee dans le rapport de temps de perequation au cours des essais a des succions matrices SWCC superieures a la valeur d'entree d'air du sol. [Traduit par la Redaction] Mots-cles: sol non sature, anisotropie hydraulique, permeabilite, courbe caracteristique sol-eau, experience en laboratoire., Introduction Hydraulic characteristics of soil are described mainly by its permeability and its soil-water characteristic curve (SWCC). Coefficient of permeability relates flow rate to driving potential, which is primarily due [...]