Abstract: In this study，we investigated genetic structure of 8 maize inbred line with 59 SSR markers. The results showed that inbred line Ji 853 has most high genetic similarity coefficient（GS=0.71）with inbred line Huang zao si, but has rather genetic difference（GS=0.55）with inbred line Zi 330. There were four types for alleles flow from inbred line Huang zao si and Zi 330 in the genetic background of inbred line ji 853. The proportion of first type loci from both parents was 26.67%. These loci belonged to non-recombinant loci. The second type from inbred line Huang zao si’s alleles was 33.33%. The third type from inbred line Zi 330’s alleles was 11.67%. The forth type that was different from inbred line Huang zao si and inbred line Zi 330’s alleles was 28.33%. The recombinant loci focused on four regions (Bin2.0-Bin2.03, Bin3.02-Bin3.05, Bin5.01-Bin5.04 and Bin8.08). These mutations greatly enriched genetic diversity of inbred line Ji 853. This study proved that second cycle inbred lines is still an important breeding methods in future because of considerable mutations happened in selection of second cycle inbred lines.