The DIRT(Detritus input removal and transfer) experiment was established near a 1 ha forest ecosystem long term observation stand in Quercus acutissima forest in Jiaozuo State Forest Farm,Henan Province.Four treatments were set up in this DIRT experiment including DL(Double litter,i.e.twice aboveground litter inputs),NL(No litter,i.e.aboveground litter excluded from plots),NI(No input,i.e.aboveground litter and around roots excluded from plot) and CK(Control,normal litter inputs).The soil available phosphorus of 0—10 cm and 10—20 cm soil layers were measured for continuous 2 years,the change rate,change velocity,month to month growth rate and year to year growth rate of soil available phosphorus were calculated,so as to clarify the impact of litter input change on the available phosphorus content in ground soil in Quercus acutissima forest in warm temperate zone,provide reference for further study on the soil available phosphorus dynamic,and provide basis for further study on ecosystem response to global climate change.The results indicated that the soil available phosphorus content had seasonal change,lower in spring and early summer,higher in autumn and winter;the soil available phosphorus content of 0—10 cm layer was higher than that of 10—20 cm layer,but there was no significant difference,the relationship could be expressed with power function.At 0—10 cm layer,DL treatment increased the soil available phosphorus content,while NL and NI treatments reduced soil available phosphorus content,but there was no significant difference between these treatments,while the change rate of soil available phosphorus content had significant difference.The change velocity of soil available phosphorus content narrowed its fluctuation range,while the month to month growth rate and year to year growth rate of soil available phosphorus content expanded its fluctuation range in the late stage;these indexes had no significant differences among different treatments,respectively.The litter input treatment and season change had significant impact on soil available phosphorus content at 0—10 cm layer,but little at 10—20 cm layer.The research clearly showed that different treatment of litter input mainly affect the soil available phosphorus content of 0—10 cm soil layer,but weakly affect that of 10—20 cm soil layer;the seasonal change affects the soil available phosphorus either.