Physical properties of three types of paddy soil collected from south Kiangsu prowince were studied. The shearing strength of paddy soils increases with the decrease of moisture content, especially below the lower plastic limit. Maximum compressibility appears at the high moisture content and it falls sharply near the middle part of plasticity range. As compared with the soils of heavy texture, the light paddy soils have a higher compressibility and lowering soil water content to a greater extent is necessary to reduce their compression. The soil moisture causes shrinkage, especially for soils of heavy texture. Shrinkage makes the paddy soils more compact than mechanical pressure. It is suggested therefore that the optimum soil moisture for the fall cultivation ranges from lower plastic limit to the medium plasticity and for the spring cultivation the optimum moisture content may be higher than in the fall.