The experiment was conducted to study effects of inulin on the growth performance, indices of immune organs and serum immunoglobulin of laying chicklings as well as the performance of inulin which replaced the antibiotics in diets by adding 0.2%, 0.4% and 0.8% of inulin, respectively. Four hundred 1-day-old Hyline brown laying chicklings were randomly divided into 5 groups with 4 replicates per group of 20 chicklings per replicate. Group I was the control group fed basal diet while the others were the experimental groups fed the diet with 0.2%, 0.4% and 0.8% inulin and antibiotics, respectively. The experiment lasted for five weeks. Results showed that inulin of above percentages in the diet had not significant influence on the average daily feed intake (P＞0.05), and adding 0.8% inulin and antibiotics in the diet of laying chicklings had significant effects on average daily gain, feed∶gain, livability, indices of immune organs, IgA and IgG (P＜0.05). It was concluded that adding inulin to diet could increase immune organ indices, improve the level of serum immunoglobulin and growth performance of laying chicklings. Adding 0.8% inulin to the diet showed the best performance, which could be used in substituting some function of the antibiotics.