Through the field survey and laboratory analysis, this paper studied the impact on soil aggregate and infiltration capability after forestland converted into tea garden. The results showed that the water-stable aggregates of the forestland and 30 years-tea garden (30 years) were dominated by macro-aggregates (> 5 mm), and the soil micro-aggregates (< 0.25 mm) was the highest in newly-reclaimed young tea garden (3 years). After the conversion from forestland into tea garden, in 0—20 cm depth, the soil R0.25 (water-stable aggregate > 0.25 mm), mean weight diameter (MWD), geometric mean diameter (GWD), initial infiltration rate, average infiltration rate, stable infiltration rate, cumulative infiltration in 30 min and cumulative infiltration significantly decreased by 10.59%~19.38%, 30.32%~65.60%, 44.04%~72.08%, 49.97%~76.62%, 51.04%~73.90%, 51.90%~55.66%, 55.61%~78.82% and 59.65%~69.23% (P< 0.05) respectively, and the fractal dimension (D) significantly increased by 4.61%~7.52% (P< 0.05). The soil R0.25, MWD, GWD, initial infiltration rate, average infiltration rate, stable infiltration rate, cumulative infiltration in 30 min and cumulative infiltration were in the order of forestland > 30 years-tea garden > newly-reclaimed young tea garden, and D varied as the opposite trend simultaneously. Pearson correlation analysis showed that soil infiltration properties in different plots had a extremely significant positive correlation with R0.25, MWD, GWD and >5 mm macro-aggregates, and a significant or extremely negative correlation with D, 1~2, 0.5~1, 0.25~0.5 and <0.25 mm micro-aggregates. The eigenvalues of soil aggregate and infiltration capability (except the D) had extremely significant positive correlation with soil organic carbon, available nitrogen, available potassium, soil porosity and field capacity, and showed extremely significant negative correlation with soil bulk density, but not significant correlation with soil pH and available phosphorus. In summary, soil water-stable aggregate (especially the >5 mm macro-aggregates) contents were decreased dramatically after forestland converted into tea garden, consequently reducing the soil aggregates stability and also the soil infiltration capability. With the increasing tea plantation age, the soil organic carbon and available nutrients were also improved, which could increase the soil macro-aggregates content, leading to the improved soil aggregate and infiltration capability, but still not reach the level of forest.