β-Cyclodextrin-N-vinyl-2-pyrrolidone (CDM-NVP) copolymer was prepared by free radical chain reaction of N-vinyl-2-pyrrolidone (NVP) and β-CD maleate (CDM) with γ-ray as initiator.The synthesis conditions of CDM-NVP polymer were as follows: mass ratio of CDM to NVP was 1∶0.7 (CDM 3.6 g and NVP 2.52 g), irradiation dosage was 4 kGy, and DMF aqueous solution (50%, V/V) was set at 20 mL.Under the synthesis conditions, the yield of CDM-NVP was 84% and the weight-average molecular weight was 20 kD.The natamycin (NM) and carbendazim (MBC) could form stable inclusion complexes with CDM-NVP copolymer, and the solubility and fungicidal activity of the complexes were investigated.The stability constant of NM·CDM-NVP and MBC·CDM-NVP complexes at 303 K were 12, 988.54 L/mol and 865.94 L/mol, respectively.The complexes were characterized using phase solubility diagrams, nuclear magnetic resonance (NMR) spectra and ultraviolet (UV) spectra.The analysis of the biological activities of these two complexes indicated that they possessed enhancing fungicidal activities compared to NM and MBC alone.