Abstract: Abstract: The characterization of genetic backgrounds is favorable to select good near-isogenic lines (NILs). Seventeen Near-isogenic lines (N1-N17) for fertility restorer genes of K-type cytoplasmic male sterility (CMS) in wheat were bred By successive backcrossing and individual selection，and their agronomic characters such as plant height, spike number per plant, length of the flag leaf, width of the flag leaf, length of the second leaf under spike, neck length, length of the first joint under spike, length of the second joint under spike, spike length and spikelet number were measured. Genetic difference comparisons between the NILs and the K-type sterile line and clustering analysis were carried out in this paper. The results indicated that the genetic backgrounds of 17 NILs were highly accordant to that of the sterile line after 5 successive backcrossing. N14, N1, N7, N16, N15 and the sterile line Yumai 3 were classed into the same group, but N1 and N15 had greater variation, so N14, N7 and N16 were better NILs.