Abstract:The present research evaluated the effects of the frequency of freeze-thaw cycles (FTC) (0, 3, and 9 times) and initial soil water content (WC) (40%, 60%, and 80% field capacity) on soil aggregate distribution and four aggregate associated available trace elements (Cu, Fe, Mn, Zn) in a typical Chinese pine forest soil in the Wangmaogou watershed. The results showed that FTC significantly increased the proportion of aggregates < 0.25 mm (P<0.01), decreased the proportion of aggregates >2 mm (P<0.01), thus significantly decreased the mean weight diameter (MWD) (P<0.01). Increased soil WC significantly decreased the proportion of aggregates <0.25 mm, increased the proportion of aggregates 0.25~2 mm and >2 mm, thus increased MWD. The increased effects of soil WC on MWD were much larger than the disruptive effects under FTC conditions. FTC significantly decreased the total amount of available Cu and Fe, and increased the total amount of Mn and Zn in < 0.25 mm aggregates. The total amount of the four available trace elements in>2 mm aggregates were significantly increased after FTC. Increased soil WC decreased the available trace elements content in <0.25 mm aggregates and increased in the >2 mm aggregates. The increased soil WC could offset the disruptive effects of FTC on soil aggregation, and FTC and the increase soil WC synergistically improved the available tract elements contents in >2 mm aggregate fractions.