Interplanting grass is one of the important orchard floor management measures for avoiding negative potential effects, such as soil erosion, soil organic matter decrease, soil fertility reduction and deterioration of fruit quality induced by traditional orchard clean cultivation activities. The effect of interplanting grass on soil organic carbon and its active components is very critical for implementing soil ecological management, promoting the system of organic fruit production and improving the soil quality in orchards. Therefore, this study focused on addressing the issues relating to the effect of interplanting ryegrass (Lolium perenne L.) and hair vetch (Vicia villosa Roth) in peach orchard on soil total organic carbon (TOC) and its fractions, including microbial biomass carbon (MBC), water-soluble organic carbon (WSOC), light fraction organic carbon (LFOC), heavy fraction organic carbon (HFOC) and aggregates organic carbon. The results showed that compared to the clean cultivation control (CK), TOC, MBC and WSOC in interplanting ryegrass treatment (RG) were significantly increased by 5.13%, 76.4% and 18.1%, respectively. For hair vetch treatment (HV), LFOC and HFOC were significantly increased by 11.3% and decreased by 13.2% respectively when they are compared with CK. However, soil TOC, MBC and WSOC had no significant changes in HV. In addition, RG significantly raised the content of larger size fraction (> 74 μm) aggregates of soil organic carbon, and reduced the smaller size fraction (< 2000 μm). As for TOC improvement effect, interplanting ryegrass seemed to be better than hair vetch in peach orchard. MBC, WSOC, LFOC and HFOC can be served as sensitive indices for characterizing the changes of soil quality and soil organic carbon in peach orchards.