【Objective】To elucidate the effects of freeze-thaw cycles and initial water content on soil structure, rare earth oxides(REOs)were used as tracers to separate soil aggregates formation and breakdown processes. 【Method】REOs-labelled soil was reformed and investigated herein. Two initial water contents(50% field water holding capacity(T50)vs. 100% field water holding capacity (T100)) and five freeze-thaw cycles (0, 3, 6, 12 and 20 cycles) were involved in the simulation experiments. Soil aggregates distribution, mean weight diameter (MWD), and the aggregate turnover process were measured accordingly. 【Result】The results showed that freeze-thaw cycles significantly reduced MWD, > 0.25 mm aggregates and < 0.053 mm aggregates proportions, but increased the contents of 0.25～0.053 mm aggregates under the same initial water content. After 6 freeze-thaw cycles, MWD was significantly (P< 0.05) higher under T50 compared with that under T100, but there were no significant differences between the contents of 5～2 mm and < 0.25 mm aggregates. Except for 5～2 mm aggregates, the intensive transformation between neighboring size aggregates was observed during the whole simulation experiments. In the same freeze-thaw cycles, the transformation proportions from 5～2 mm to 0.25～0.053 mm aggregate were significantly (P < 0.05) higher under T100 compared with T50 treatment. The freeze-thaw cycles promoted the breakdown of > 0.25 mm aggregates and the formation of 0.25～0.053 mm aggregates both under T50 and T100 treatments. Also, MWD was significantly positively correlated with the relative formation of soil aggregates and negatively related with the relative breakdown of soil aggregates (P < 0.05). The turnover time of soil aggregate remarkably increased with the freeze-thaw cycles (P < 0.05) and the aggregate turnover time of > 0.25 mm aggregates was higher than that of < 0.25 mm aggregates. Comparatively, the aggregate turnover time was significantly higher under T100 than that under T50 with the same freeze-thaw cycle (P < 0.05). 【Conclusion】The freeze-thaw cycles and soil initial water content significantly affect the aggregate turnover. Both parameters change the stability of soil structure by affecting the aggregate formation and fragmentation processes. The results provide a theoretical basis for further exploration of the structural changes of black soil under freeze-thaw cycles.