The distribution and formation of water-stable aggregates in karst soils under different land use were studied. The results showed that the contents of >0.25m m water-stable aggregates changed in the following order:shrub grassland > woo dland > old field > orchard > farmland
and the content of >2mm water-stable so il aggregates is more in the surface and subsurface soils of woodland and shrub grassland than in orchard
old field and farmland. Either the water-stability of aggregates or the content of water-stable aggregates was highly correlated with the contents of soil organic matter. Increased decomposition and decreased input of organic matter after reclamation were responsible for the decrease in b oth the water-stability of aggregate and the amount of water-stable aggregates in karst soils. The soil aggregate structure may be rehabilitated after returni ng farmland to woodland or grassland.