Abstract: 【Objective】 Mikania micrantha is one of the key invasive species in China. To screen and utilize local plants that had competitive advantages over Mikania micrantha for replacing control， which could provide scientific basis for implementing ecological control and restoration through the use of replacing species combination. 【Method】 This study used Cymbopogon winterianus and Ipomoea batatas as replacing species， which had competitive ability on Mikania micrantha. Through pot experiments and field experiments， the competitive effects and inhibitory effects of different density combinations of the two species on Mikania micrantha were determined and evaluated， and interaction effects were analyzed and synergistic effect combinations of replacing control were screened. 【Result】 The results of pot experiment showed that both Cymbopogon winterianus and Ipomoea batatas had competitive advantages and replacing control effects on the growth of Mikania micrantha. The competitive balance indexes （CBa） of monoculture on Mikania micrantha were 0.214 and 0.294 respectively. The results of the plastic greenhouse experiment for measuring the plant interaction effects and screening for synergistic combinations showed that when Cymbopogon winterianus and Ipomoea batatas were planted alone at a density of 80000 plant/ha， their actual inhibition rates against Mikania micrantha were 54.1% and 63.0% respectively. By using different density combinations of the two replacing species to control Mikania micrantha， antagonistic， additive or synergistic interaction effects could be produced. Among them， the combination of Cymbopogon winterianus and Ipomoea batatas at planting densities of 1∶2 to 1∶4 exhibited synergistic effect， which greatly enhanced the competitive ability and inhibitory effect against Mikania micrantha. The CBa of the combination against Mikania micrantha was 1.413 to 1.749， and the actual inhibition rate was 72.6% to 91.6%. Cymbopogon winterianus and Ipomoea batatas were combined in ratio of 1∶2 to 1∶4 as synergistic combinations and applied in the invaded grassland by Mikania micrantha. The relative density， relative frequency and relative dominance of Mikania micrantha in the community were significantly decreased compared with the blank control （P<0.05， the same below）； their importance values were 0.017 to 0.027， which were lower or significantly lower than those of the blank control and the treatments using the two alternative species alone； the plant diversity index was above 0.263 and the species richness index was above 0.223， both of which were significantly higher than those of the blank control and the other combination treatments. 【Conclusion】 When using the synergistic combination of planting density ratios of 1∶2 to 1∶4 for Cymbopogon winterianus and Ipomoea batatas， it can significantly enhance the competitive advantage and replacing control effect against Mikania micrantha. Through proper intercropping， the importance value of invasive plants in the community can be reduced and the diversity of local plants can be increased.