Abstract: The selection of participating factors and the determination of gradation indices are essential to soil evaluation. The evaluation factors should be selected respectively in accordance with the following G utilization types, dry land, paddy field, vegetable garden, orchard, forest land and range land. The main limitiing factors should be selected, that are important effect to the growth/development, and the productivity of the -utilization type or the crop combination, and are highly stable, in accordance with the soil characteristics and environmental conditions.Quantitative indices should be used in the gradation of the participating factors.Critical biological indices should be used as much as possible for the main grades. A participating factor may vary with region and utilizationtype.This paper describes the selected participating factors, that are suitable to the G utilization types nationally, and the gradation indices that divide the participating factors into 4 grades and 5 classes.

Key words: Participating factor, Gradation index, Soil evaluation