The aim of this experiment was to study the effects of dietary crude fiber levels on growth perform-ance,slaughter performance,intestinal development and cecal flora structure of Zhongxin ducks.A total of 600 one-day-old male commercial Zhongxin ducks were randomly divided into 3 groups with 8 replicates per group and 25 ducks per replicate.The dietary crude fiber levels were low(2.9%in the starter and 3.6%in the finish-er),medium(4.2%in the starter and 4.7%in the finisher)and high(5.8%in the starter and 5.5%in the fin-isher),respectively.The experimental period was 37 days.The results showed as follows:1)dietary crude fi-ber levels had no significant effect on the growth performance of Zhongxin ducks at all stages(P>0.05).2)The abdominal fat percentage of high crude fiber level group was significantly higher than that of low crude fi-ber level group(P<0.05).3)The relative weight of jejunum and ileum and proventriculus index of high crude fiber level group were significantly higher than those of low and medium crude fiber level groups(P<0.05),and the absolute weight of jejunum and ileum of medium and high crude fiber level groups were significantly higher than those of low crude fiber level group(P<0.05).Dietary crude fiber levels had no significant effect on the intestinal injury score of Zhongxin ducks(P>0.05).4)The Shannon index of medium crude fiber level group was significantly higher than that of high crude fiber level group(P<0.05).At the phylum level,the relative abundance of Firmicutes was the highest in medium crude fiber level group,while the relative abun-dance of Bacteroidetes was the highest in low crude fiber level group.At the genus level,the relative abun-dance of Bacteroides was the highest in low crude fiber level group.In conclusion,Zhongxin ducks feeding medium crude fiber level(4.2%in the starter and 4.7%in the finisher)dites showed the best growth perform-ance and cecal flora structure;feeding high crude fiber level(5.8%in the early stage and 5.5%in the late stage)diets are beneficial for the gastrointestinal tract development of Zhongxin ducks,but it may have adverse effects on growth performance and slaughter performance.[Chinese Journal of Animal Nutrition,2023,35(12):7805-7816]