The dynamic changes of water regime in sloping uncultivated red soil derived from Quaternary red clay distributed in Jiangxi Province were investigated during 1990-1993.Resuits show that the water regime in sloping red soil changed apparently not only in a year but also between years.The water content of red soil under high water potential is higher.However,in connection with the specific structural characteristic,the available water content in red soil is lower,which becomes an inner important factor leading crops to subject draught hazard in Summer and Autumn.The water storage in sloping red soil is richer in the first half of a year,then decreased from the beginning of July in the second half of the year.In later time a negative value of available water content appeared at soil depth of 0-50 cm.Results also shows that according to the ratio of the measured water storage of soil to the calculated rhaximum storing water capacity a certain amount of empty water storing capacity at soil depth of 0-100 cm where can accept the rainfall could be found even though in first half of a year with richer rainfall.Moreover,a richer water storage at soil depths of 100-200 cm and 200-300 cm is presented in the second half of a year with severe shortage of rainfall.Consequently,to increase the acceptance of rainfall in first half of a year and to use the richer water storage in deeper soil layers in the second half of a year are an effective way for raising the use efficiency of water resource in red soils.