In this study, the differences between oligochitosan (MW 1,000~3,000 Da, C1K) and two compounds [Gallic acid (P-GA) and 3,4-dihydroxybenzoic acid (P-DHBA), Comps] purified from Terminalia nigrovenulosa bark (or two commercial compounds) and mixtures of C1K and Comps were investigated for their antioxidant activities (DPPH radical scavenging activity and total antioxidant capacity) and antifungal against Fusarium solani. The EC50 values of C1K for antifungal activity were in the range of 358.6-745.1 ppm. Both C1K and mixtures of C1K and Comps strongly inhibited mycelium growth of F. solani after 2 and 4 days incubation. Mixtures of C1K and Comps had high antioxidant activity in terms of both DPPH radical scavenging activity and total antioxidant capacity. These results suggested that mixtures of C1K and Comps triggered mechanism for the enhancement of suppressive activity to the phytopathogen F. solani and antioxidant activities.