This paper presents a study about the effects of the structure on the erodibility of residual soils of gneiss. This study considers four soils, three saprolitic and one lateritic, from the city of Joinville, state of Santa Catarina, in southern Brazil. Experimental campaign comprises infiltrability and loss of mass by immersion tests to achieve erodibility of such soils. Such tests compose the MCT methodology. These tests were conducted on undisturbed and remolded samples, under natural moisture and air dried during 24, 48 and 96 hours. Grain-size distribution curves were obtained in tests with and without the use of dispersant solution. The suppressing of dispersant solution results in grading curves distinct from that obtained by standardized tests, which means that different erodibility parameter for USLE model can be obtained for the same soil. According to erodibility tests, the lateritic soil has low erodibility potential when compared to saprolitic soils. It agrees with in situ observations. Damaging soil structure makes the soils more susceptible to erosion process, mainly the saprolitic ones. In general, remolding is more effective to increase the erodibility than soil drying.