Abstract: To study effects of interplantation ratio on cadmium accumulation of two ecotypes (farmland and mining) of Bi?dens pilosa, a pot experiment, designed to have six treatments in ratio, i.e. 1:4, 2:3, 3 :2, 4:1, farmland ecotype only and mining ecotype only, and the soil spiked with 10 mg•kg^-1 cadmium, was conducted. Results demonstrate that as compared with their respective treatments of monoculture interplantation increased the farmland ecotype of B. pilosa bio?mass, but decreased the mining ecotype of B. pilosa in biomass per plant, and significantly increased the contents of chlorophyll a, chlorophyll b and carotenoid in the two ecotypes of B. pilosa, and the concentration of cadmium in various or gans of the two ecotypes of B. pilosa. When the interplantation ratio was 2:3 (farmland ecotype:mining ecotype),thecontent of cadmium was the highest in all organs of the two ecotypes of B. pilosa, and the cadmium accumulation in theshoots and the whole plant in one pot were also the highest, reaching up to 422.08 and 477.91 μg•pot^-1 , respectively.To sum up, the interplantation of the two ecotypes of B. pilosa at a ratio of 2 : 3 (farmland ecotype ∶ mining ecotype) may effectively improve the plants′ cadmium accumulation capacity, and consequently the effect of the two ecotypes of B. pilosa remedying cadmium contaminated soils.