Mechanical stability of aggregate is a key factor influencing soil resistance to erosion. To investigate the variations of aggregate tensile strength for zonal soils and their stabilization mechanisms, aggregates of different sizes (1~2, 2~3, 3~5 and 5~10 mm) for six typical zonal soils (Cinnamon soil, Yellow-cinnamon soils, Brownish red soils, Red soils, Latosolic red soils and Latosols) in central-southern China were selected. In the study, the tensile strength and their relationships with soil physicochemical properties were examined. Main results were shown as follows: (1) With the increase of hydrothermal condition, soil pH and kaolinite content gradually decreased from north to south, while opposite trends were displayed in free iron (Fed) and aluminum (Ald) oxides. The content of organic matter decreased with soil depth. (2) All these soils were in heavy texture. Aggregate tensile strength generally decreased with the increase of aggregate size. For the same size aggregates, tensile strength showed a decreased trend from north to south in China. (3) Tensile strength was correlated positively with pH, silt content and vermiculite content significantly (R>0.63, p<0.01), while negatively with clay content, 1.4 nm transition mineral content, kaolinite content, Fed and Ald (R<-0.53, p<0.05). (4) Multiple stepwise regression showed that the Fed and cation exchange capacity could be used to better predict and evaluate tensile strength of 3~5 mm aggregate (R2=0.80, p<0.01). In general, the types and amount of clay mineral play a vital role in aggregate mechanical strength for zonal soils. The results?can?provide?a?basis?for?the?prediction?of?soil?erosion?and?decision-making?for?soil and water conservation.