[Objective] The objective of this study is to explain relationship between soil biology and abiological characteristics on crude-oil contaminated soil and provide basic data and background information for its comprehensive remediation in eastern Gansu Province. [Methods] The changes of soil physical and chemical properties as well as enzyme activities in crude oil-contaminated soil in Qingyang City of Gansu Province were investigated using the conventional methods, and the genetic diversity of microbial community was analyzed based on PCR-DGGE. [Results] The contents of soil available N, available P, pH value and activity of soil urease decreased with the increase of soil TPHs concentration respectively(p<0.01), while the activities of soil polyphenoloxidase, dehydrogenase and catalase had a significant positive correlation with soil TPHs concentration respectively(p<0.01). As for the genetic diversity of soil microbial communities, Shannon-Wiener index in the studied sites with lower TPHs concentration was significantly higher than that of the sites with higher TPHs concentration(p<0.05). Moreover, nonmetric multidimensional scaling(NMDS) showed that petroleum-contaminated soil in Gansu Province were strongly affected by soil available N and available P, and following-affected by soil TPHs concentration, pH value, urease activity, Shannon-Wiener index of soil microbial communities and activity of soil catalase.[Conclusion] Impact of crude oil pollution on soil environmental factors in Eastern Gansu Province of Loess Plateau was mainly reflected by the nutrients effective circulation of nitrogen and phosphorus as well as soil microbial-communities diversity and soil urease activity, but there were no significant impact on available K, richness and evenness of soil microbial communities.