Abstract: Comparative studies on the chemical factors in humus layer and 0～10 and 10～20cm soil layers at the main succession stages of evergreen broad-leaved forest in Tiantong, Zhejiang Province show that as succession proceeded, the total N content increased distinctly,but the contents of NO₃^--N,NH₄⁺-N and available N,P and K had no distinct increase. No obvious variation was found for soil pH. Soil organic matter content increased distinctly, and the amounts of humic acid(HA) and fulvic acid(FA) were relatively high in Castanopsis fagasii and C.fagasii＋Schima superba forests and lowest in bare land. The HA/FA in humus layer didn't show any obvious pattern, but decreased in 0～10 and 10～20cm soil layers. The results suggested that the secondary succession of evergreen broad-leaved forest could increase soil organic matter, and promote its mineralization and re-synthesis. On the other hand, the improvement of soil chemical properties could also provide better prerequisite for progressive succession of evergreen broad-leaved forest.

Key words: Subtropical evergreen broad-leaved forest, Secondary succession, Soil nutrient, Soil organic matter, soil respiration, land restoration, soil bulk density, microaggregates, maize yield