The aquatic plant (Ipomoea aquatica), aquatic animal (filter feeding Hyriopsis cumingii), artificial medium for an integrated ecological floating bed (IEFB) were combined, and the contaminant removal rates contributed by different biological units were analyzed. It is shown that, the artificial medium (microorganism) unit acted as the main role of purification of IEFB with approximately 48.5%, 46.7%, and 49.9% of TN, TP and CODMn removed from the water, respectively, much higher than that of aquatic plant unit and aquatic animal unit. Furthermore, the contribution of aquatic animal unit for chlorophyll a removal was 79.1%, which means that the particulate organic matters filter fed by the Hyriopsis cumingii is the main contaminations removal way of aquatic unit. The filter feeding and ammonia emission effect of the Hyriopsis cumingii promotes the solubilization and mineralization of particulate organic matters, which provides advantaged substance condition for the microorganism attached to the artificial medium of IEFB, and resulting in promoting the purification efficiency of the floating bed.