Abstract: With the enhancement of the suspect's counter-surveillance ability and the increase of the complexity of the samples, forensic DNA phenotypic inference has been explored in the disciplinary applications, among which single nucleotide polymorphism (SNP) has shown great potential for development in courtroom science by virtue of the advantages of its small fragment size and multiple methods, which is expected to push courtroom science to a new height. However, due to the immaturity of related technology and analysis methods, it needs a lot of experimental research to improve its accuracy to reach the standard of practical application. The progress of SNP inferred phenotypes, the challenges and future prospects of SNPs in terms of pigmentation, height, facial features, male pattern baldness, etc. are discussed in this paper, so as to provide references for the application of SNPs in courtroom science.