〔Abstract〕 Objective To explore the interaction between risperidone(RI) and bovine serum albumin(BSA) on the presence of polyinosinic-polycytidylic acid(Poly I:C), and the effects of metal ions(Mn2+,Cu2+,Cr3+,Mg2+,Co3+) on the interaction. Methods The interaction of quenching type and mechanism were determined using UV-visible absorption spectroscopy and fluorescence spectroscopy. Hill curve was used to study the synergistic effect of drug combination. The values of the quenching constant, quenching rate constant, the binding constant and the number of binding sites were calculated according to the Stern-Volmer equation and its modified equation. Thermodynamic parameters and type of interactions were obtained be obtained from Vanʼt Hoff equation. Results In presence of Poly I:C, the fluorescence of BSA was quenched by Poly I:C and RI, which was a dynamic quenching process. The interaction of RI and BSA with Poly I:C was mainly driven by hydrogen bond and Vander Waals force. Location of the primary binding site for Poly I:C and RI was on the sub-domain ⅡA of BSA. When Poly I:C and RI bound to BSA simultaneously, the values of Hill′s coefficients were close to one, which indicated that there was no cooperative effect. The conjugation reaction between Poly I:C-RI and BSA would hardly impact on the BSA conformation, and the binding site was closer to tryptophan residue. Conclusion The addition of Poly I:C played a positive role in enhancing the efficacy of RI. The presence of common metals affected the binding of Poly I:C and RI to BSA. This work will provide scientific reference for their clinical application of RI and Poly I:C combined with medication.