Taking the rhizosphere soil of Red Fuji′ apple trees at different ages in Yichuan county as research object, the relationships between fruiting periods and rhizosphere soil environmental factors, including microbial biomass carbon (MBC), enzyme activities and nutrient composition, were investigated, so as to offer reference for the scientific cultivation and management of apple trees in Loess Plateau. The rhizosphere soil MBC, enzyme activities and nutrient composition were measured using chloroform fumigation extraction as well as physical and chemical analysis. Multivariate analysis was used to analyze the relationship between the characteristics of rhizosphere soil and the growth stages of apple trees. The results showed that: (1) MBC in rhizosphere soil increased during the tree ages of 3~7 a and 7~10 a, then decreased significantly (P

apple tree age；rhizosphere soil;microbial biomass carbon（MBC）；nutrients；enzyme activities;principal component analysis（PCA）