In this study, we had established a 16S rDNA-DGGE analys is system to detect the microbial community in petroleum polluted soil and assess the feasibility of using this system to monitor the bioremediation process. Three genomic DNA extracted methods, the KIT, the Bead-beating system, and the Freeze-thaw method were used to evaluate the DNA extraction efficiency and purity. These DNA samples were further tested by DGGE to analysis the microbial community in soil samples. The results showed that KIT method performed advantageous not only in the DNA extraction efficiency and purity, but also expressed the richest bacterial community in its PCR products. From the DGGE analysis, our data indicated that composition of bacterial community were different in the soil samples that were taken from the same site but at different time. This indicated that the species and number of microorganisms in a polluted soil were under a dynamic transition. The combination of DGGE and 16S rDNA gene sequence analysis system were also proven useful in identifying the predominant microbes in a soil sample and monitoring its bacterial community.