To remove high-strength perchlorate, dissimilatory perchlorate reducing granular sludge (DPR-GS) was first cultivated. Three identical UASB reactors were set up under different seed sludge and up-flow velocities (R-AS: active sludge (AS) and constant up-flow velocities; R-DGS: denitrifying granular sludge (DGS) and constant upflow velocities; RDGS-f: DGS and fluctuating up-flow velocities). The AS in the R-AS was completely granulated by day 117, while the DGS in the R-DGS and RDGS-f were both shortened the granulation time to 99 days. In addition, the fluctuating up-flow velocity can better ensure rapid cultivation of DPR-GS. Removal of ClO4- loading rate with 7.20 kg/(m(3).d) occurred in all three reactors. The results of extracellular polymeric substances (EPS) composition analysis indicated the polysaccharose (PS) promoted the formation of bio-aggregates, while the protein (PN) benefited the granulation of sludge. The analyses of the microbial communities indicated that Sulfurospirillum and Acinetobacter were the dominant dissimilatory perchlorate reducing bacteria.