A region (200 kb) of Contig. 060226.1 on GGA1 was selected to study the average diversity of Red Jungle Fowl (RJF), Taihe Silk chicken (TS), and White Recessive Rock (WRR), and estimate the effective population size (Ne) of chicken. The mean heterozygosities of RJF, TS and WRR were 0.28533±0.034747, 0.32926±0.039191 and 0.30168±0.040382, respectively. Significant test indicted that there is not significant difference between them (P=0.2368>0.05). The initial chicken effective population size was estimated to be about 20 000-150 000. Chicken has undergone serious population bottleneck effect during the first stage of domestication. However, this bottleneck effect did not result in a substantial loss of diversity as revealed by SNP. The possible explanations for similar SNP diversity between domesticated chicken and Red Jungle Fowl might due to many factors, such as a big Ne in earlier phase of domestication, population expending in breed differentiation, abroad crossing between breeds (especially crossing with RJF), together with high recombination rate in chicken genome.