In order to develop a new plant-resource Citrus reticulata preservative, the inhibitory effects of water extracts from five plants were evaluated by antibacterial test, and the inhibition effects of Houttuynia cordata and Syzygium aromaticum and pullulan polysaccharide composite on Penicillium italicum after harvest were studied. The results showed that the Syzygium aromaticum and Houttuynia cordata water extracts had better inhibitory effect on Penicillium italicum, the inhibition ratios were 73.45% and 49.85% respectively, and the MIC were 0.60 mg/mL and 1.20 mg/mL respectively. The mixed Syzygium aromaticum and Houttuynia cordata water extracts had higher inhibitory toxicity than that of single water extracts, and the EC50 was 0.36 mg/mL. The decay rate of the compound preservative was 16.67% lower than that of CK group (p<0.05), but the inhibition effect on weight loss rate was not significant (p>0.05) after 9 days storage. The compound preservative could effectively delayed the increase of soluble solid content and titratable acidity content, maintained stable ascorbic acid content and inhibited the respiration intensity. The experimental results indicated that Syzygium aromaticum and Houttuynia cordata water extracts could inhibit spore germination and mycelial growth in Penicillium italicum; the compound preservative of Houttuynia cordata and Syzygium aromaticum and pullulan polysaccharide could improve the resistance of Penicillium italicum of Citrus reticulata. This study provides theoretical support for the development of new safe preservative of Citrus reticulate.