Study of genome-wide SNPs, mitochondrial DNA and Y-chromosomal DNA variation can provide a valuable information about the population structure and peopling of human populations. To explain a genetic homogeneity of Koreans and population structure of Koreans and the East Asian populations, we analyzed 153 individuals from the Korea and 77 individuals from the East Asia at 46,559 common single-nucleotide polymorphic loci. The 137 CHB and 113 JPT individuals at 25,769 common SNPs from the International HapMap project were further analyzed to reveal the population structure of the East Asians. Principal Component analyses (PCA) and population differentiation ( ) are examined. In the PCA test, the Jeju individuals were slightly different from other Koreans but their values were not significant. This reflect the genetic homogeneity of Korea population. In general, all the individual samples studied here were clustered into subset of ethnic origin according to their geographical location except Mongolians. Whole genome sequencing of Koreans and other population genome by next generation sequencing technology will provide great opportunity to understand the population expansion and peopling of Korea better.