Abstract:Autoclaving sterilization, which was usually used for soil sterilization, was generally to evaluate the effect of autochthonous microorganisms on the study purpose. But the physical, chemical and microbiological properties of soil samples which were autoclaved may changed during the sterilization process, and then led to the effect of autochthonous microorganisms was covered up. Basic propertie, including organic matter(OM), specific surface area (SSA), pH, cation-exchange capacity (CEC), free iron/ aluminium oxides(Fed,Ald) and zero point of charge (ZPC), of the eight typical soils(Usti-Sandic primosols, Usti-Alluvic Primosols, Hapli-Stagnic Anthrosols, Gleyi-Stagnic Anthrosols, Ferri-Udic cambosols, Argi-Argiudic Ferrosols, Alliti-Argiudic Ferrosols, Rhodi-Udic Ferralosols) in China were analysed in this study. The value of bacteria, fungi, and actinomycetes were also analysed to determine the effect of the sterilization treatment. The results showed that the OM was not affected by autoclaving excepted for Usti-Sandic primosol and Ferri-Udic cambosols. The pH varied obviously in the soils which had lower pH and higher organic matter content, while changed little in the soils with higher pH and lower organic matter content. The SSA of all the studied soil decreased significantly after sterilization, while there was no significant change for CEC and Fed,Ald between unsterilized and sterilized soils. The zero point of charge (ZPC) of the four variable charge soils was titrated, and the results showed that ZPC of the Ferri-Udic cambosols was decreased by autoclaving, while ZPC of the other three soils was not changed. Although the value of bacteria, fungi, and actinomycetes were decreased significantly after autoclaving, the ideal condition of disappearance of all was not achieved. It is possible that more phenomena and mechanism in soil autoclaving are required to validate the finding.