This study aimed to explore the characteristics of the vertical distribution of the conversion between soil erosion degrees by taking the Yimeng mountainous area

one of the most representative areas in the rocky area of Northern China

as a case study.The study was based on the national standards for classification and gradation of soil erosion and supported by the GIS and RS technology and the data from Landsat TM image and relief map.Results showed that from 1986 to 2004

soil erosion was mainly converted to minimal degree and adjacent degrees.The area of aggravated soil erosion was 810.7 km2 and the area of alleviated soil erosion was 1913.8 km2

accounting for 7.15% and 16.88% of the total changed area

respectively.About 81.51% of the aggravated areas and 73.43% of the alleviated areas occurred between 150 and 400 m above mean sea level.The areas for all the soil erosion degrees ascended at first and then descended subsequently with rising elevation.Elevation for peak value of the erosion area rose with increased soil erosion degree.Elevation ranges for minimal

slight

and moderate erosion degrees rose with increased soil erosion degree.Locations of the elevation range from intense

very intense

and severe erosion to minimal degree were relatively low and those from very intense and severe erosion to moderate degree were relatively high.