Abstract: To investigate the permeability anisotropy of intact and remolded granite residual soils, a series of multi-directional saturated permeability tests were conducted on completely weathered granite residual soil from Guangzhou, China. Saturated hydraulic conductivity was measured along different seepage directions, and scanning electron microscopy (SEM) together with pore-size distribution analysis was employed to elucidate the microstructural mechanisms governing permeability anisotropy. The results show that the intact soil, which preserves a structural pore system formed by long-term weathering and eluviation, exhibits pronounced directional dependence: the hydraulic conductivity in the horizontal direction is markedly higher than that in the vertical direction, and a distinct minimum value occurs at a seepage angle of 45°or 60° from vertical direction. Microstructural observations further indicate that the vertical direction is dominated by eluviation-induced micropores, whereas the horizontal direction contains a higher proportion of meso- to macropores with stronger connectivity; differences in pore-size distribution and pore connectivity constitute the primary structural basis for the observed permeability anisotropy. In contrast, the compacted remolded soil shows a continuous and monotonic variation of hydraulic conductivity with seepage angle, exhibiting evident transverse isotropy in seepage, and the measured k(θ) agrees well with the theory of permeability prediction. This study reveals the fundamental differences in permeability anisotropy between intact and remolded states of granite residual soil, providing experimental supports for parameter selection and model formulation in saturated seepage analysis and slope stability evaluation.