[Objective] The present study aimed to establish a rapid method for the isolation of small amount DNA from citrus.[Method] By using the improved CTBA method,the genomic DNA was extracted respectively from 20,10,5 and 2.5 mg hybrid embryos of citrus,and then the DNA quality was detected and followed by SSR verification.[Result] The method was very simple and rapid,which needed less materials.In addition,the isolated DNA showed good purity with the OD260/OD280 of 1.8-2.1,and could meet the requirement for PCR-based technology,such as SSR,etc..[Conclusion] The method could be used for rapid extraction of small amount of genomic DNA from citrus.