The microbial molecular ecology techniques, which were developed on the basis of molecular, were applied in studying the bacteria in Constructed Rapid Infiltration （CRI） system. These techniques are very efficient in better describing the bacterial diversity, microbial community distribution, and relations between microbial group structure and nitrogen contamination through the analysis of microbial nucleic acid sequence fragment in CRI. The results further revealed the removal mechanism of contamination, which is essential for the improvement of wastewater treatment in CRI.
