Soil siderophores are important for crop growth, benefit ferric iron absorption of root, and are affected by cropping patterns. The objective of this study was to evaluate the quantity of siderophores in soil of 2 continuous crop rotation patterns over 30 years in Anren country, China. Quantity and siderophore-producing capability of microorganisms in rice-riceoilseed rape(DDY) rotation and rice-rice(DD) rontinuous cropping rhizosphere soil were tested and analyzed by chrome azurol S method. Isolated strains were used to identify siderophore-producing microorganism(SPM) by PCR amplification and DNA sequencing.Results showed that 9 siderophore-producing bacteria strains were isolated from DDY rhizosphere soil while 7 strains were identified from DD rhizosphere soil. The mean solubility index which representing siderophore-producing capability of strains was 3.05. PCR amplification results indicated that bacterial were the major SPM in soil. This research indicates that crop rotation systems could drive microorganisms to produce siderophores and enrich them in bacterial communities.