To establish a foundation for further researches on the improvement of polymorphonuclear neutrophil leukocytes (PMN) functions in dairy cow during perinatal period, the counting of PMN, as well as the mRNA and protein expression of toll-like receptor-4 (TLR-4) on PMN was studied during this critical period. Blood samples were taken 21, 14 and 7 days, and at calving (0) day before expected calving time, and 7, 14 and 21 days after calving. The PMN changes were measured by automatic blood cell analyzer, and mRNA and protein expression of TLR-4 were analyzed by quantity real-time PCR (RT-PCR) and western blot. The results show that the quantity of neutrophil leukocytes reached the peak (3.12 ± 0.26 × 10 9 , p