Purpose of the present work is to show evidence supporting the hypothesis that nitrate reduction products pro-duced by one type of partial denitrifiers could be used as electron acceptor by other type of part ial denitrifiers.This mechanism of soil denitrificat ion, here referred to as successive denitrification, differed from the commonly accepted mechanism in that the former was conducted by different types of partial denitrifers while the later was done by complete denitrifiers.Soils sampled from the Changshu Agroecosystem Experimental Station, Institute of Soil Science, Chinese Academy of Sciences were enriched with soil extract plus N₂O as the sole electron acceptor.Bacteria in the enriched materials were isolated using 1/10 diluted nutrient broth under anaerobic condit ion.The isolates were characterized by reduction of nitrogen oxides.Partial denitrifying strains were obtained.The strain coded as 21-6-9-2 was able to reduce NO₃^- to NO₂^- only, the strain coded as 1-9-5-3 able to reduce NO₂^- to N₂O only and the strain coded as 21-6-3-6 able to reduce NO₂^- to N₂ only.When strain 21-6-9-2 and strain 1-9-5-3 were mixed with proper ratio into sterile soil, without adding any additional carbon substrate, NO₃^- was reduced to N₂O, demonstrating that the partial denitrifiers could cooperate in use of the substrate and play a similar role to that typical denitrifiers do.