The difference between conventional permeability test and triaxial permeability test is studied and the characteristics of saturated loess permeability affected by stress field by confining pressure are analyzed.The loess samples from the four typical loess areas of Lanzhou

Luochuan

Yangling

and Gongyi were fully saturated to make conventional variable-head permeability test and triaxial permeability test.Results show that with the increases in confining pressure and dry density

the permeability coefficient of saturated loess decreases.In general

when dry density changes from 1.45 g/cm3to 1.65 g/cm3and confining pressure

from 100 to 400 kPa

the permeability coefficient by triaxial permeability test is almost 0.881 to 0.161 times less than the test result of conventional permeability.