The study was conducted to determine blood haematological and biochemical parameters of 8 week-old Co Lung ducksraised atDai Xuyen Duck Research Center. Blood samples were collected from 60 healthy ducks (30 males and 30 females). The results showed that the blood physiological and biochemical parameters of the ducks varied within the normal ranges withthe total red blood cell count (RBC) of 2.82 million, haemoglobin concentration (Hb) of 12.18g%, hematocrit(HCT) of 44,30%, platelet cell (PLC) of 23.85 x 103/mm3), mean corpuscular volume (MCV) of 158,60fL, mean corpuscular haemoglobin (MCH) of 43.44 pg, mean corpuscular haemoglobin concentration (MCHC) of 27.98 g/dl, total white blood count (WBC) of 39.72 thousand/mm3. The percentage of eosinophil, basophil, neutrophils, monocyte and lymphocyte were 7.06; 3.06; 24.43; 12.08,and 53.35%, respectively. There were no significant differencesbetweet males and females in biochemical parameters,exceptforα2 -globulin. The biochemical parameters of blood plasma were: albumin 17.61g/l, total protein 34.12g/l. Protein fraction contained3.01, 7.47, 4,02,and 1.00g/l for α1-globulin, α2-globulin, β-globulin and γ-globulin, respectively.