Using rapeseed oil as the only carbon source,a thermostable acid lipase strain CQNU 3-3 was isolated from the sewage of the school dining hall through enrichment,domestication,screening and re-screening.The analysis of morphology,physiological and biochemical characteristics,the phylogeny of 16S rDNA sequence indicated that the strain CQNU 3-3 was as a member of Delftia tsuruhatensis and named Delftia tsuruhatensis strain CQNU 3-3.The analysis on the effects of fermentation conditions to the production of enzyme showed that the enzyme activity was the highest at the initial pH 2,the suitable fermentation temperature was 32-37 ℃.The study on enzymatic properties of lipase showed that the optimum reaction pH was 7.0,the reaction temperature was 50 ℃.Zn~(2+) and EDTA could significantly increase the enzyme activity and Cu~(2+),Mg~(2+),Na+and urea could significantly decrease the enzyme activity.Additionally,the degradation rate of the added oil in the sample was high to 73.54%.