Abstract: Single nucleotide polymorphisms (SNPs) were developed as a new generation molecular marker in recent years. They were the variation between individuals and populations because of single nucleotide base alteration, including transition, transversion, insertion and deletion. It was first used in the association analysis between diseases or populations’ variation in phenotypes and mutation in single nucleotide bases. With the development of detection methods and relevant databases, it became an important tool in revealing the genetic evolution, analyzing the intrinsic causes of the extrinsic characteristics, etc. In this paper we reviewed the features, detection methods, application areas and foregrounds of SNPs.