Abstract: The author systematically analyzed the planting methods among Iris pseudacorus, Scirpus validus and Acorus calamus with normal planting density but different planting models which were pure plantation, mixed by group plants, and mixed by individual plant. The results showed that I. pseudacorus and A. calamus possessed relatively higher elongation rate (ER) under the mixture plantation method than pure plantation. The average growth rate (AGR) of I. pseudacorus was somewhat higher than that under pure plantation. However, it was the contrary for A. calamus. When I. pseudacorus and A. calamus was planted with S. validus respectively, the ER of S. validus under the mixture plantation model was statistically higher than that under pure plantation, while I. pseudacorus and A. calamus exhibited relatively lower ER than that under pure plantation. In addition, when mixed by individual plant, the AGR of I. pseudacorus and S. validus were lower than that under pure plantation. The AGR of A. calamus was lower under the model mixed by group plants than that under pure plantation, but turned to equals between the planting methods of mixed by individual plant and pure plantation. These results indicated that when I. pseudacorus and A. calamus were mix-planted with each other, they could promote a relatively higher rapid ratio in the elongation of the stem and faster accumulation of biomass, showing facilitation. On the contrary, when these two species were planted with S. validus separately, the latter would exhibit a faster elongation in the stem to restrain the former two.