The study was carried out to evaluate the effect of tree age on soil physical properties and erodibility. The organic matter content was 54 and 46% significantly higher in soils under agro-forestry than that in control soils in surface and subsurface soil layers, respectively. It was maximum in 6 years plantation followed by 3 years and minimum in one year plantation. The mean weight diameter (MWD) of wet aggregates was significantly higher (8 and 5.2 times) in surface and subsurface soils under agro-forestry compared to that in control soils, respectively. It significantly increased with increase in tree age. The bigger aggregates (>0.1mm) were more in soils under agro-forestry than in control soils, whereas the smaller ones (<0.1mm) dominated in control soils. The bigger aggregates (>0.1mm) increased significantly with increase in tree age, whereas smaller aggregates were more in one year plantation. The total porosity was significantly higher under agro-forestry than that in control soils. The increase in total porosity was significantly maximum in 6 years plantation. The water holding capacity (WHC) was significantly higher (11.8 and 9%) in soils under agro-forestry than in control soils in surface and subsurface soil layers, respectively. It significantly increased with increase in tree age. The dispersion ratio was 76.5 and 30% lower in surface and subsurface soils, respectively, under agro-forestry than in control. It significantly decreased with increase in the age of the trees. The water stable aggregates (WSA) >0.5mm was significantly higher, 19.8 and 14.9 times in surface and subsurface soils, respectively, under agro-forestry than in control. The WSA>0.5mm significantly increased with increase in tree age. Thus, agro-forestry improves the soil physical environment and reduces erodibility of soils.