Oxygen-enriched gasification of single-feed refuse-derived fuel (RDF) and dry sewage sludge (DSS) in a laboratory-scale fluidized bed was investigated. The optimal temperature, equivalence ratio (ER), and oxygen concentration of RDF and DSS gasification were 800 degrees C, 0.292, 50% and 750 degrees C, 0.321, 44.7%, respectively. The low heating values (LHVs) and cold gas efficiency (eta values) of syngases from RDF and DSS were 6.79 MJ/Nm(3), 53.0% and 6.51 MJ/Nm(3), 49.2%, respectively, under optimal conditions. To improve the quality of DSS syngas, the effect of the RDF mixing ratio on RDF and DSS cogasification was investigated at 800 degrees C, with an ER of 0.321 and an OC of 44.7%. The gas yield increased continuously with increased RDF mixing ratio, and eta rose to 55.0% with relatively high LHV of producer gas at a 25% mixing ratio of RDF.