Abstract: To study the effects of ultra-fine powder of Senecio scandens on growth performance and some serum biochemical indices in piglets, 90 pigs (Duroc×Landrace×Yorkshire) were selected at an initial body weight about 10.0 kg, with randomized block design and male and female account for half respectively. The piglets were divided into 5 groups, each group contained 3 pens and each pen contained 6 piglets. The piglets in groupⅠwere fed with basic diet, 75 mg/kg chlortetracycline and 20 mg/kg colistin sulfate were added in basic diet for groupⅡ, and 0.4%, 0.8%, 1.2% of ultra-fine powder of S. scandens were supplemented in basic diet for groupⅢ, groupⅣand groupⅤ, respectively. The piglets were raised for 30 days. The results showed that adding ultra-fine powder of S. scandens increased the average daily gain and the average daily feed intake and reduced the ratio of feed and meat, among which the addition of 0.8% of the ultra-fine powder significantly increased the average daily gain (P＜0.05) and reduced the ratio of feed and meat (P＞0.05), without difference between groupⅡand groupⅣ(P＞0.05). Adding ultra-fine powder of S. scandens improved serum GLU, TG, T3, T4, IGF-I levels and reduced the level of serum BUN, among which the addition of 0.8% of the ultra-fine powder significantly increased the levels of serum T3 and IGF-I (P＜0.05), and significantly reduced the concentration of serum BUN (P＜0.05). In conclusion, adding 0.8% of the ultra-fine powder of S. scandens markedly improved the growth performance of the piglet and significantly increased the average daily gain, the levels of serum T3 and IGF-I, but significantly reduced the ratio of feed and meat and the concentration of serum BUN.