In this study, b-cyclodextrin (b-CD) was used to form an inclusion complex with peony seed oil (PSO), in order to improve its stability, transport convenience and bioavailability. Single-factor optimisation method was applied to determine the optimum inclusion conditions. The inclusion complexes were prepared by saturated solution method and characterised by GC-MS, SEM, FT-IR, XRD, DSC and 1 H NMR analyses. All results suggested that PSO was successfully entered into the b-CD cavity. What is more, inclusion rate of PSO reached 68.72 AE 2.14%, resulting in a product of 25.97% PSO content, and the unsaturated fatty acids, similar to PSO, accounted for 90.05% of all fat acids in complex. The linolenic acid in inclusion complex exhibited 64.84% higher bioavailability than that in PSO. The inclusion complex possessed of better stability for storage and transportation. Overall, the fabricated complex improved the feature of PSO and thus could be used for novel applications. Inclusion complex of PSO with b-CD X. Sun et al. 2353 d Half-life in vivo.Inclusion complex of PSO with b-CD X. Sun et al.