The aim of this study was to determine the changes of somel hematological parameters in experimental coccidia-infected Luong Phuong chicken caused by Eimeria fenella. Fourty coccidia-free chickeps were selected, raised in dean cages and were periodically screened for Eimeria infection status by microscopical fecal examination. Two weeks later, the chickens were distributed into 2 groups, experimental and control groups, 20 chickens in each. The experimental group was inoculated orally with sporulated oocyst of E. fenella at the dose rate of 1 x 105/chicken, while control group was given orally PBS solution. After one week, all chickens were bled by cardiac puncture to determine hematological parameters. The results indicated that number of erythrocytes, hemoglobin volume, and hematocrit decreased. In contrary, the mean corpuscular volume increased, while mean corpuscular hemoglobin, mean corpuscular hemoglobin concentrations and red cell distribution width remained unchanged. The number of leukocytes increased and its formula was changed, number of neutrophils and eosinophils increased, in the case of lymphocytes decreased. The total protein of serum, its formula and AIG ratio decreased and the formula of corpuscular globulins were also changed as compared with control group chickens.