Abstract: In order to improve the aspergillus niger corrosion resistance of eucalyptus/polyvinyl chloride (PVC) composites, TiO₂ was added to prepare TiO₂-eucalyptus/PVC composites. The TiO₂-eucalyptus/PVC composites were subjected to the mold accelerated corrosion test, the accelerated corrosion conditions:the temperature was 28℃ and the humidity was 85%. The color difference, mechanical properties, water absorption performance, the functional groups, microtopography and thermal stability of TiO₂-eucalyptus/PVC composites before and after corrosion were tested and analyzed. The results show that TiO₂ can improve the mold corrosion resistance of eucalyptus/PVC composite. The TiO₂-eucalyptus/PVC composites present less mold phase when the TiO₂ adding amount is 2wt% after corrosion. The color difference and water absorption of TiO₂-eucalyptus/PVC composites decrease by 69.32% and 13.33% respectively in comparison to the composites without TiO₂. And the tensile strength, impact strength, bending strength and bending modulus of TiO₂-eucalyptus/PVC composites increase by 31.17%, 39.44%, 40.75% and 10.99%, respectively. The 2wt%TiO₂-eucalyptus/PVC composite obtained at higher thermal decomposition temperature in each stage indicates the better thermal stability. The more TiO₂ content will affect the interface of eucalyptus fiber and PVC, making it to be more susceptible to mold corrosion.