This experiment was conducted to study the effects of dietary niacin supplemental level on laying performance, egg quality and serum biochemical indices of breeding geese during laying period. A total of 180 thirty-four-week-old breeding geese with the similar body condition were randomly divided into 6 groups with 6 replicates per group and 5 geese per replicate (1 male and 4 female). Geese in the 6 groups (groups Ⅰ to Ⅵ) were fed experimental diets supplemented with 0, 10, 20, 30, 40 and 50 mg/kg niacin, respectively. The pre-experimental period lasted for 1 week, and the experimental period lasted for 10 weeks. The results showed as follows:1) dietary niacin supplemental level had no significant effects on the average daily feed intake, laying rate and average egg weight of breeding geese during laying period (P>0.05). When dietary niacin supplemental level was 40 mg/kg, the average daily feed intake, laying rate and average egg weight got the maximal value. The feed to egg ratio of group Ⅴ was significantly higher than that of groups Ⅰ and Ⅱ (P<0.05). 2) Dietary niacin supplemental level had no significant effects on egg shape index, albumen height, yolk color, yolk ratio and Haugh unit of breeding geese during laying period (P>0.05). The eggshell strength of group Ⅴ was significantly higher than that of groups Ⅰ, Ⅱ and Ⅲ (P<0.05), and the eggshell thickness of group Ⅴ was significantly higher than that of groups Ⅰ and Ⅱ (P<0.05). 3) Dietary niacin supplemental level had no significant effects on contents of total protein, albumin, glucose and uric acid and activity of glutamic oxaloacetic transaminase in serum of breeding geese during laying period (P>0.05). The serum triglyceride content of groups Ⅳ, Ⅴ and Ⅵ was significantly lower than that of groups Ⅰ and Ⅱ(P<0.05), the serum total cholesterol content of groups Ⅲ, Ⅳ, Ⅴ and Ⅵ was significantly lower than that of group Ⅰ(P<0.05), the serum low density lipoprotein-cholesterol content of groups Ⅰ was significantly higher than of other groups (P<0.05 or P<0.01) and the serum high density lipoprotein-cholesterol content of groups Ⅴ and Ⅵ was significantly higher than that of group Ⅰ (P<0.05 or P<0.01). In conclusion, dietary niacin can reduce the feed to egg ratio of breeding geese during laying period, improve the eggshell thickness and eggshell strength, decrease the contents of triglyceride, total cholesterol and low density lipoprotein-cholesterol in serum, improve the serum high density lipoprotein-cholesterol content. It is suggested that the dietary niacin supplemental level of breeding geese during laying period is 40 mg/kg, at present, the dietary total niacin content is 69.16 mg/kg.