Abstract:Phospholipid fatty acids (PLFAs) analysis method and PCR-denaturing gradient gel electrophoresis (DGGE) technology were used to investigate microbial structure and population diversity of the soil sampled from the three areas of the mulberry orchard, which was contaminated by polycyclic aromatic hydrocarbons (PAHs). The results of PLFAs analysis showed that total PLFA biomass of the microbes in area 2 was the highest, most of which were the bacteria and fungi. Clustering analysis of soil microbes revealed that the PLFAs were mainly divided into three groups. Redundancy analysis demonstrated that PAHs pollution degree had a certain effect on soil microbial community structure. DGGE fingerprint analysis showed that there were more electrophoresis bands in the areas with higher PAHs contamination, and the difference of Shannon index and Simpson dominance degree were significant among three areas. Population dominance degree of the soil in area 2 was the highest. Principal components analysis of DGGE profiles indicated that there were significant differences in population structure of the microbes in different area.