Abstract: Changes in physical structure of red soil were studied under different conditions of fertilizer application.The results showed that the content of ＞1mm mechanical-stable macro-aggregate was increased while the content of ＞1mm water-stable macro-aggregate decreased after red soil was cultivated,but applications of organic fertilizers were beneficial to buffer the decline tendency of content of ＞1mm water-stable macro-aggregate,and to increase total macro-aggregate content of ＞0.25mm.Soil porosity was increased while soil bulk density was decreased after red soil cultivated.Soil capillary porosity was increased by 50%,and soil available water capacity increased by 64% under application of organic fertilizers,while application of chemical fertilizers only increased by 27% and 33% respectively.Meanwhile,there was a significant increase in soil reserving water capacity under application of organic fertilizers,but there was no significant difference between application of chemical fertilizers and uncultivated soil.