This experiment was conducted to study the effects of dietary iodine supplemental level on growth performance, slaughter performance, nutrient utilization and nutrient utilization of Wulong geese, and to determine the suitable dietary iodine supplemental level of Wulong geese. A total of 360 four-weeks-old healthy Wulong geese were randomly divided into 6 groups with 6 replicates per group and 10 geese per replicate. Geese in group Ⅰ (control group) were fed a basal diet without iodine supplementation, and the others in the experimental groups (groups Ⅱ to Ⅵ) were fed experimental diets supplemented with 0.15, 0.30, 0.60, 1.20 and 2.40 mg/kg iodine, respectively. The experiment lasted for 12 weeks. The results showed as follows: 1) the average daily gain of group Ⅲ was significantly higher than that of groups Ⅰ, Ⅱ, Ⅴ and Ⅵ (P<0.05 or P<0.01), the average daily feed intake of group Ⅲ was significantly higher than that of groups Ⅰ, Ⅱ, Ⅳ and Ⅵ (P<0.05), the feed to gain ratio of group Ⅲ was significantly lower than that of groups Ⅰ, Ⅱ and Ⅴ (P<0.05 or P<0.01). 2) the dressing percentage, percentage of half-eviscerated yield, percentage of eviscerated yield of group Ⅲ were significantly higher than those of group Ⅰ (P<0.01), the percentage of breast muscle of group Ⅲ was significantly higher than that of groups Ⅰ, Ⅳ, Ⅳ and Ⅵ (P<0.05), the percentage of leg muscle of group Ⅲ was significantly higher than that of groups Ⅰ, Ⅱ, Ⅴ and Ⅵ (P<0.05 or P<0.01), the percentage of abdominal fat of group Ⅲ was significantly lower than that of groups Ⅰ, Ⅱ and Ⅵ (P<0.05 or P<0.01). 3) The crude protein utilization of group Ⅲ was significantly higher than that of groups Ⅰ, Ⅱ, Ⅴ and Ⅵ (P<0.05 or P<0.01), the ether extract and crude ash utilizations of group Ⅲ were significantly higher than those of groups Ⅰ, Ⅴ and Ⅵ (P<0.05 or P<0.01), the calcium utilization of group Ⅲ was significantly higher than that of groups Ⅰ and Ⅵ (P<0.05 or P<0.01), the phosphorus utilization of group Ⅲ was significantly higher than that of groups Ⅰ, Ⅴ and Ⅵ (P<0.05 or P<0.01), the neutral detergent fiber utilization of group Ⅲ was significantly higher than that of group Ⅰ (P<0.05), the acid detergent fiber utilization of group Ⅲ was significantly higher than that of groups Ⅰ, Ⅴ and Ⅵ (P<0.05 or P<0.01). 4) The deposit nitrogen and deposition efficiency were significantly higher than those of groups Ⅰ, Ⅱ and Ⅵ (P<0.05 or P<0.01). In conclusion, dietary addition of iodine can improve the growth performance, slaughtering performance and nutrient utilization of Wulong geese, the suitable dietary iodine supplemental level of Wulong geese aged from 5 to 16 weeks is 0.30 mg/kg.