In order to explore aggregate structure of long-term pear planting soil and its effect on soil organic carbon, pear planting soils in Liangli Town, Dangshan County, which has a total of 12 years from 10 to 300 years, were used as the research object, and the farmland soil near pear orchard was used as a control. Soil aggregate size distribution (0-20 cm), organic carbon contents in soils and aggregates were studied in order to explore the correlation between soil aggregates and organic carbon for long-term pear planting. The results showed that with the increase of planting years, the content of soil macro-aggregates (>0.25 mm) increased first, then decreased slightly and tended to stabilize, reached a maximum value (798.8 g/kg) in 150 years. The contents of soil total organic carbon and organic carbon of macro-aggregates significantly increased by 1.45 times and 2.24 times respectively compared with the control (P<0.05), while organic carbon content of micro-aggregates (<0.25 mm) decreased significantly. Soil organic carbon was mainly contributed by large aggregates, with the contribution rate of 68.06%-98.78%, which was 28.3%-59.02% higher than that of control (39.76%). The contribution rate of micro-aggregate decreased with year, indicating that the long-term pear planting promoted the distribution of organic carbon from micro-aggregate to macro-aggregate. There was a significant positive correlation between the contents of macro-aggregates and organic carbon (P<0.01), and they all increased first and then decreased to a stable trend with year. It shows that pear planting is beneficial to improve soil structure and increase carbon sequestration potential of the soil.