Abstract:Three wetland species, Canna indica Linn., Cyperus flabelliformis Rottb., and Hymenocallis littoralis (Jack.) Salisb., were grown in solution culture systems in a climate chamber, and the growth characteristics and dissolved organic carbon exudates (DOC) of roots were studied. The results showed that Canna indica and Cyperus flabelliformis had similar total biomass and root biomass, and similar amount of DOC, which were significantly higher than those of H. littoralis (P<0.01). However, production of DOC per unit root biomass was similar for the three species. DOC of the three wetland plants were positively correlated with total biomass (P<0.01) and root biomass (P<0.01).