Single nucleotide polymorphisms (SNPs) have been very widely used in the study of diseases and characters since the completion of the Human Genome Project. SNPs are mostly used as mere genetic markers in studying complex disease. Geneticists began to focus on the direct relationship between SNPs and complex diseases after the "Encyclopedia Of DNA Elements Project". SNPs can pay a regulative role alone, while the collected SNPs in genome can significantly affect the biological characters and disease development.