This study was conducted to obtain the information about injury caused by continuous cropping of peony
(Paeonia lactiflora). Soil physico-chemical properties, characteristics of microbial distribution and diversities
in the continuous cropped field with peony were analyzed. As the results, pH and organic matter content were
higher in the continuous cropping soil than those in the first cropping soil. Bulk density was decreased but
porosity was increased in the continuous cropping soil. As the cultivation period was lengthened in years, the
populations of bacteria and actinomyces were gradually decreased, whereas fungal population was increased.
It was shown that the metabolic diversity patterns of the microbial communities in the continuous cropping
soil differed from that of the first cropping soil. These results indicate that deterioration of soil quality such as
physico-chemical properties including a soil depth, bulk density, porosity and soil pH is related with a
continuous cultivation periods, and also affect a microbial population, especially fungi.