Copy number variations (CNVs) refer as a DNA segment that is 1 kb or larger and is presented at a variable copy number in comparison with a reference genome. Classes of CNVs include insertions, deletions, duplications and their complex combinations. Because they widely distributed in the genome with some important characteristics, such as heritable, relative stable and heterogeneity, CNVs are considered as novel genomic polymorphism markers. And the alteration of gene dosage which resulted from CNVs could change phenotype, so a novel CNV genome-wide association analysis (CNV-GWAS) strategy appeared recently and began to used for identifying susceptible genes of complex diseases. It was approved that it could complement the tranditional genome-wide association studies based on single nucleotide polymorphisms. Therefore, genomic structure variances are favorable for revealing the molecular mechanisms and genetic foundation of complex diseases.