【Objective】 This study isolated diesel degradable bacteria and optimized their growth conditions.【Method】 Diesel degradable bacteria were isolated from petroleum contaminated soil in Qingyang and Zhongyuan oil fields by enrichment culture and plate streaking methods using diesel as the sole carbon source and their diesel degradation efficiency was measured by ultraviolet spectrophotometry.The growth conditions(pH and temperature) of strains with high growth rate as well as high diesel degradation efficiency...