The effect of soil compaction and clod distribution of two clayey soils on the growth of rice in southern Jiangsu province was studied. The distribution of soil clods in the plough layer under different ploughing methods was also investigated. The results obtained denoted that the compaction and the proportion of soil clod and fine soil particles influenced the growth of rice markedly. The effect of soil compaction on the growth of rice was produced by the mechanical resistance of soil to the penetration of roots, the inhibition of nutrient transformation and the unfavorable physical properties of soil moisture. The mineralization of soil nutrients might be mainly affected by soil clodding. Grinding the soil in water might promote the release of NH₄-N. The release of NH₄-N was obviously less in clod >1 cm in diameter. Therefore, it is suggested that the quantity of soil clod <1 cm in diameter in the plough layer may be taken as an important index for the evaluation of spring ploughing.