This experiment was conducted to investigate the effects of selenium (Se) source and level on growth performance, carcass traits, antioxidative ability and meat quality of broilers.  A total of 320 one-d-old Arbor Acres commercial broilers were randomly assigned to 1 of 5 treatments with 8 replicates in a completely randomized design involving a 2×2 factorial arrangement of treatments plus one Se-unsupplemented basal diet control for 42 d.  The two Se sources were sodium selenite and Se yeast, and the two supplemental Se levels were 0.20 and 0.40 mg Se kg^–1.  The results showed that broilers fed the Se-supplemented diets had higher (P<0.05) average daily gain and average daily feed intake from 22 to 42 d of age, eviscerated yield and abdominal fat percentages, Se concentrations and glutathione peroxidase (GSH-Px) activities in breast and thigh muscles on d 42, and lower (P<0.05) feed/gain from 1 to 21 and 22 to 42 d of age, mortality from 22 to 42 d of age and malondialdehyde (MDA) concentration in thigh muscle on d 42 than those fed the control diet.  Broilers fed the diets supplemented with Se yeast had higher (P<0.05) pH value and lower (P<0.05) shear force in thigh muscle than those fed the diets supplemented with sodium selenite.  Additionally, broilers fed the diets supplemented with 0.40 mg Se kg^–1 had lower (P<0.05) shear force in thigh muscle and higher (P<0.05) GSH-Px activities in breast and thigh muscles than those fed the diets supplemented with 0.20 mg Se kg^–1.  Furthermore, broilers fed the diet supplemented with Se yeast at 0.40 mg Se kg^–1 had higher (P<0.05) Se concentrations in breast and thigh muscles than those fed the diet supplemented with Se yeast at 0.20 mg Se kg^–1, but no differences (P<0.05) were observed in these indices of broilers fed the diets supplemented with sodium selenite between 0.20 and 0.40 mg Se kg^–1.  The results from the present study indicated that supplemental Se could increase the growth performance, muscle Se concentration and antioxidative ability of broilers; and the Se from Se yeast was more effective than the Se from sodium selenite in improving meat quality of broilers.