Changes in the physical properties of high-yield paddy soil in.Tiaxing,Zhejiang Province after seven-year application of organic materials were analyzed.Different physical properties of soils in different treatments and the effect of application time of organic materical were compared after wheat hardiest and later rice harvest.Results show that although the organic matter content of the soil used in the experiment was as high as 35.5 g/kg,the physical properties of high-yield paddy soil were improved significantly by applying organic material.The soil bulk density and rupture modules decreased but the soil porosity and 1-0.05 mm micraag gregates increased.Meanwhile,its effectiveness was elosely related to different moisture cola ditions.Applying organic material into waterunsatutated.soil in wheat season was more effecrive than that into water-saturated soil in early rice season.Moreover,soils treated with orgenie materials,were moxe loose and had a quicker increase of air-filled porosity than the soil of control treatment,which wa}uld he beneficial to the sowing of upland crop as early as posBible after rice harvest.