As soil ages,its contents of Sr,Ba and Sr/Be decrease,and the contents of V,Sc,Ni,Cr,Co as well as Fe/Ni and Fe/Co rise,which was discovered in a study on soils of different soil ages,developed on basalts in the north Hainan Island.Ba/Nb,significantly,correlative with soil ages can be used to evaluate soil development.By the mass-balance method to element migration was discussed with Ti as immobile element.The results show that elements leach most extremely in weakly-developed soils.In this period (Entisols),over 90 per cent of Ca,Mg,K and Na were lost,out of solum till ferrosols formation.The leaching of P occurred mainly in the beginning of soil development.About 60 per cent of Si lost in the stage of Cambisols and 80 per cent in the stage of Ferralisols.