Abstract: The soil fertility variation of Eucalyptus robusta plantation community and adjacent areas was studied by using Grey System Relational Analysis in Mid-Yunnan.The results showed that during the growing seasons,because of human disturbance,Eucalyptus robusta plantation in the fragile ecological area had great demands of nutrient especially in rainy season,which made the soil fertility decreased from 0.274 ± 0.027 in dry season to 0.256 ± 0.018 in rainy season.It aslo showed a lasting exhaust to the soil fertility during the year,comparing to the adjacent communities which tended to cause the soil depletion of ecosystem and then affected the restoration of the vegetation.Based on our study,it was suggested that an artificial management of the soil nutrient was needed in order to realize a persist development of eucalypts industrial.