Abstract: Soil sample were collected from paddy fields different in mushroom residue application rate for analysis in laboratory of compostiton and stability of soil aggregates.Results show that application of mushroom residue change the distribution of soil aggreates to a certain extent.All in all, soil aggregates > 2.0, 0.5-1.0 and 0.25-0.5mm were dominant fractions, regardless of treatment (mushroom residue application rate). Application of mushroom residue increased the content of >2.0 mm soil aggregates, and the higher the mushroom residue application rate, the higher, the content of > 2.0mm soil aggregates. Mean weight diameter (MWD) and geometric mean diameter (GMD) increased with rising mushroom residue application rate (except for MR3), while fractal dimension (D) decreased with the rising rate. Correlation analysis shows that MWD is significant and positively related to GMD, and the contents of > 2.0  and 1.0~2.0 mm soil aggregates are significantly and positively related to MWD and GMD, but negatively related to D, though not significantly. MWD and GMD could be used as indices in evaluating stability of > 2.0  and 1.0-2.0 mm soil aggregates in soils applied with mushroom residue.

Key words: mushroom residue, soil aggregate, paddy field, stability