Bacteria rich in capsule are widely applied in many fields and it is important to investigate their gene resources. But capsules, especially capsule polysaccharides, will disturb DNA extracting largely, thus, LiCl precipitating method was introduced in this paper as a novel method and was examined by electrophoresis, spectrophotometer and amplification of 16S rRNA gene. Results showed that it could extract genomic DNA about 23 kb effectively in molecular weight from bacteria rich in capsule polysaccharides, and doesn't need purification for following serial molecular biological experiments.