To examine the effects of altered precipitation pattern on the mechanism of forest soil carbon(C)emission under climate change scenarios,we established plots with 50% reduction in throughfall in a subtropical Pinus massoniana plantation.The effects of throughfall reduction on the mineralization of both soil and aggregate-associated organic C were quantified by laboratory incubation at constant temperature.The results showed that the cumulative mineralization of organic C in the 1-2 mm aggregates was higher than that in other sizes of aggregates.In the dry and wet seasons,the surface soil water content in the throughfall reduction plots was 82.1% and 82.7% of that in the control,but the mass fractions of 0.106-0.25 mm soil aggregates in the throughfall reduction plots increased by 1.8% and 4.2% than the control,respectively.The throughfall reduction treatment significantly reduced the mineralization rate of labile C pools(k_1)of soil and micro-aggregates in the dry season,increased the mineralization rate of recalcitrant C pool(k_2)of soil and <1 mm aggregates,and had no significant effects on the cumulative mineralization of soil organic C.Results from the correlation analyses revealed significant and positive correlations between k_1 of soil and that of the micro-aggregates and between k_2 of soil and that of the 0.25-1 mm aggregates.Under the influence of aggregate structure,water condition and soil organic carbon content,the throughfall reduction suppressed the mineralization of labile organic C while stimulated that of recalcitrant organic C.