Health and life-span of a person mainly depend on factors such as inheritance,living habit and environment.Among the three factors,environmental is an important one affecting the phenomenon of longevity.The study on spatial distribution of the density of longevous people of Rugao County,Jiangsu Province,shows that the over-90 rate(number of people over 90 years old per 100 000 in population) is high in some areas.It is higher in areas of well-developed loamy Cambosols and Anthrosols in the northern,eastern and southeastern part of the county than in areas of sandy Cambosols in the western part and areas of clayey and weakly-developed Cambosols in the southern part.According to the correlation and principal component analysis,available Se,Zn and B in soils were significantly correlated with the over-90 rate,and belonged to the same principal component,indicating that available Se,Zn and B or their combination in the soil of Rugao are probably the most important trace elements beneficial to the health and the life-span of the people in Rugao County.