Abstract: Both Eubacteria and Archaea community diversity and dynamicity were studied during PCP-degrading micro-aerobic granular sludge cultivation using 16S rDNA ribosomal RNA approach. Main bands of DGGE were compared with sequences. The results showed that Eubacteria and Archaea community were closely related to uncultured microorganisms. Compared the relative quantity change of different bacteria, there were aerobic, micro-aerobic and anaerobic bacterium in micro-aerobic granular sludge simultaneously. After granular sludge was domesticated by PCP, the dominant Eubacteria and Archaea for PCP degradation were related to Proteobacteria, Sphingomonas, Methanogenic bacterium and so on.