[Objective] The differences in aggregate stability and infiltration characteristics of loess under different forest and grass vegetation restoration types were compared in order to provide a theoretical basis for the optimization of ecological restoration patterns in the Loess Plateau. [Methods] Abandoned land (C1

control)

alfalfa land (C2)

natural grassland (C3)

mixed forest land of Pinus tabuliformis and Platycladus orientalis (L1)

and mixed forest land of Robinia pseudoacacia and P. orientalis (L2) were used to investigate differences in aggregate stability and infiltration characteristics and their exogenous factors. Water-stable aggregate composition and saturated hydraulic conductivity were determined by the Savinov method and a single-ring two-ponding depth infiltrometer

respectively. Mean weight diameter (MWD)

geometric mean diameter (GMD)

fractal dimension (D)

percentage of aggregate destruction (PAD)

water-stable macroaggregate content (＞0.25 mm

Mw)

and saturated hydraulic conductivity sample (Ks) were used as evaluation indicators. [Results] ① In the 0—30 cm soil layer

C1 had the lowest GMD and MWD

and GMD and MWD in forest and grass vegetation restoration types followed the order of 〔L1 and C3〕＞〔L2 and C2〕

respectively

whereas PAD and D showed the opposite order. ② In the 0—10 cm soil layer

L1 dominated the highest macroaggregate (＞0.25 mm) content (47.24%)

followed by C3 and L2

while C1 had the lowest content (24.00%). In the 10—30 cm soil layer

C3 dominated the highest macroaggregate (＞0.25 mm) content (35.41% at 10—20 cm; 27.96% at 20—30 cm)

while L2 had the lowest content (11.46% at 10—20 cm; 8.00% at 20—30 cm). ③ The variation coefficients of topsoil infiltration characteristics for different restoration types ranged from 0.001 to 0.360. The Ks (0.307 cm/min) of L1 was the highest

while the Ks (0.044 cm/min) of C1 was the lowest. ④ Aggregate stability indicators (except PAD) and Ks were significantly correlated with soil organic carbon

porosity

and bulk density. [Conclusion] The restoration of forest and grass vegetation was beneficial for improving aggregate stability and infiltration performance. Compared with natural grassland

long-term forest restoration exhibited better aggregate stability and infiltration characteristics

but those characteristics were worse for short-term forest restoration than for natural grassland. Time accumulation should be emphasized when evaluating the effects of vegetation restoration.