In the paper quantificational relationship between soil permeability of upland and soil erodibility in hilly red soil region of southern China was studied, by using simulated rainfall and Guelph Permeameter. Results showed that there were negative correlations between saturated permeability K_fs of 0-5cm top soil and erodibility factor K of soil derived from Quaternary red clay and red sandstone, and the quantificational relationship can be expressed as K≈a·K_fs^-b+c, where coefficients a, b and c were decided by soil properties.