Abstract: Soil morphology change systematically with soil development.The soil morphological characteristics had been extensively applied in judging the genesis and development of soils derived from unconsolidated parent materials (e.g.tills, loess, and fluvial, alluvial, lacustrian sediments, etc).Rarely, however, had the research on the development of soils from consolidated bedrocks been done by use of soil morphology.The soils developed from basalts erupted in different periods of Quaternary ranging from 0.01 Ma to 1.81 Ma B P, formed a chronosequence of soils in northern Hainan Island, southern China.The study on the soil chronosequence shows that soil morphological characteristics may also be applied in evaluating the development of soils from bedrocks.And the relationship between the quantitative indices of soil development and soil ages is high.Redness rating (RR), relative profile development (RPD), horizon index (HI), profile development index (PDI) as well as solum thickness increase with soil ages, of which profile development index (PDI), owing to PDI consisting of comprehensive soil characteristics and its rational rating system, is best to assess soil development.Meanwhile, it is noticeable that the soil properties used in some quantitative indices of soil development should be cancelled or added while those indices applied to study on soil development in different conditions.