This experiment was conducted to study the effects of dietary different supplemental levels of organic selenium and inorganic selenium on growth performance, slaughter performance, meat quality and breast muscle selenium content of geese aged from 29 to 70 days. A total of 300 twenty-nine-day-old Jiangnan geese with similar body weight were selected and randomly divided into 6 groups with 5 replicates per group and 10 geese per replicate. A 2 (selenium sources)×3 (selenium supplemental levels) double factor complete randomized experimental design was employed in this trial, geese in groups A, B and C were fed the basal diets supplemented with 0.2, 0.3 and 0.4 mg/kg seleno methionine (SM, as selenium), and geese in groups D, E and F were fed the basal diets supplemented with 0.2, 0.3 and 0.4 mg/kg sodium selenite (SS, as selenium). The experiment lasted for 42 days. The results showed as follows:1) different selenium sources and selenium supplemental levels and their interaction had no significant effects on the growth performance of geese (P>0.05). 2) Different selenium sources and selenium supplemental levels and their interaction had no significant effects on the slaughter performance of geese (P>0.05). The percentage of abdominal fat of geese in dietary SM supplementation group tended to decrease compared to dietary SS supplementation group (P=0.059). 3) The breast muscle water loss rate of geese in groups E and F was significantly higher lower than that in groups A, B, C and D (P<0.05), and the breast muscle pH_{24 h} of geese in groups D, E and F was significantly lower than that in groups A, B and C (P<0.05). Different selenium sources and selenium supplemental levels and their interaction had no significant effects on the shear force, pH_{45 min} and meat color value in breast muscle of geese (P>0.05). 4) When dietary supplemental levels were 0.3 and 0.4 mg/kg, the breast muscle selenium content of geese in dietary SM supplementation group was significantly higher than that in dietary SS supplementation group (P<0.05); when dietary supplemental levels were 0.2, 0.3 and 0.4 mg/kg, the breast muscle selenium content of geese in dietary SM supplementation group was significantly increased with dietary supplemental level increasing (P<0.05). In conclusion, different selenium sources and selenium supplemental levels and their interaction have no significant effects on the growth performance and slaughter performance of geese; compared with inorganic selenium, organic selenium can increase the breast muscle selenium content and meat quality of geese.