Abstract: According to the regulaities of regional variation of lateriatization degree of the eluvial soils on granites in South China, a comparison between the chemical compositions and lateritization indexes of ellucial soils on granites in Hong Kong and various areas of South China coastal region permitted the authors to find that the eluvial soils on granite in Hong Kong is characterized by incongruent climate condition at which it occurs either in its thickness and types in its lateritization degree. In this paper a further discussion is made on the causes for undeveloped eluvial soil on granite in Hong Kong and its effect on engineering properties.