Abstract: Using leaves in different growth periods of high-quality soybean varieties J-17, J-16, WX-1, WX-2 and Maverick as experimental materials, we used different methods for the genomic DNA extraction and determined the concentration of genome DNA. The DNA were tested by agarose gel electrophoresis, PCR amplification for internal control and comprehensive evaluation of the quality of different methods for DNA extraction. The results indicated that the DNA extracted with the modified CTAB method had higher quality and purity in fresh leaves period. The most of polysaccharides and polyphenolic compounds could be removed efficiently by utilizing new modified CTAB method and the new method was suitable for extracting high qualified DNA in flowering stage. This study laid the foundation of soybean moleculer bioresearch.