The Southern 2nd Paraná Plateau presents great variety of erosive processes. Two of then are expressive at a regional scale: gully erosion and tunneling erosion. At a regional scale, previous studies point to a weak correlation between the morphometry of hillslopes and the gully dimensions (r coefficient ranging from 0,04 to 0,40). Otherwise, the relationship between gullies orientation and regional joint patterns seems to be outstanding, mainly at N10-30E and N50-70E. Gully evolution during the last 15 years, by the use of aerial photographies, suggest that different lithologies of the Itararé sub-group should be important to gully erosion rates. Field attempts to estimate erosion rates between 1995 and 1997, by the use of plani-altimetric polygons, suggest that the most important erosion rates (38.19 and 177m3 per year) occur on gullies connected to main drainage system, that is, which evolution depends on the rates of subsurface water flow. Hydromorphic soils are very common in this area; they develop under the influence of either impermeable soil horizons, or shallow fresh bedrock, creating lateral subsurface flow and seepage zones on the gully walls. Tunneling erosion develops further and may create broader erosive features, under the influence of concentrated water flow into the tunneling network. At a regional scale, tunneling erosion define the main drainage axis on hillslopes. These axis often presents topographic subsidence and develop a pseudo-karstic topography, with tunnels and wells. Evidences suggest that those erosive processes are natural processes which had been acting in the region during the last 40,000 years.