Abstract: In order to study the effects of Yinglu Huangjinbao（Eucommia ulmoides leaf extract）on the growth performance,diarrhea rate and fecal microbiota of weaned piglets, 40 piglets at the age of 26±2 days were selected and randomly divided into four groups. Group 1 was basic diet control group, groups 2 to 4 were traditional Chinese medicine feeding groups, and 0.2 g/kg, 0.4 g/kg and 0.8 g/kg Huangjinbao feed additives were added to the basal diet according to body weight, respectively. The test period was 14 days, the daily weight gain, diarrhea rate, intestinal microbiota, and serum immune indicators were tested. The results showed that, compared with the control group, the Yinglu Huangjinbao could increase the average daily gain（ADG）and average daily feed intake（ADFI）of weaned piglets, as well as reduce the feed to weight ratio（F/G）（P<0.05）in the high, medium, and low dose groups. In addition, the F/G was reduced by 21.72% and the ADFI was increased by 12.21% in the low dose（0.2 g/kg BW）of weaned piglets, and the diarrhea rate was also reduced by 26.20%. Alpha diversity analysis showed ACE, Chao 1, and Shannon index were significantly increased and Simpson index was decreased in the test groups（P<0.05）, indicating an enrichment of gut microbiota diversity in weaned piglets. The antioxidant stress indicators of T-AOC, T-SOD, GSH-Px in piglet serum were significantly increased and MDA activity was significantly reduced（P<0.01）. Huangjinbao could effectively increase the average daily weight gain, reduce the feed to weight ratio and diarrhea rate, improve the antioxidant stress capacity and enrich the gut microbiota of weaned piglets.

Key words: medicinal herb, Yinglu Huangjinbao, weaned piglets, growth performance, diarrhea rate