Abstract: In order to compare the effects of glycine microelement chelate and seaweed polysaccharide microelement chelate on weaned piglets, in the experiment, 160 Duroc×Long White×Big White ternary hybrid weaned piglets with similar litter size were selected as test subjects and divided into 2 treatment groups with 4 replicates of 20 pigs each according to the principle of similar weights. The control group was fed weaning feed + glycine microelement chelate and the experimental group was fed weaning feed + seaweed polysaccharide microelement chelate for 18 d. At the end of the experiment, the average feed intake, average daily weight gain of pigs, feed weight ratio and diarrhea rate were measured and calculated. For each group, one piglet of near average body weight was selected for slaughter in each replicate, and immune organs（pancreas, spleen, lymph nodes and thymus） were taken to calculate organ indexes; tissue samples were taken from the proximal duodenum, middle jejunum and distal ileum, tissue sections were made; intestinal villus height and crypt depth were measured, and ratio of villus height to crypt depth（villus height/crypt depth） were calculated. The results showed that the average feed intake and average daily weight gain of piglets in the experimental group were 9.5% and 18.6% higher than those in the control group（P＜0.05）; the feed-to-weight ratio was reduced by 7.7%（P＜0.05）, and the diarrhea rate decreased by 48.6%（P＜0.05）. Compared with the control group, the pancreatic index and lymphatic index were increased by 20.5% and 14.9%, respectively, in the experimental group（P＜0.05）, and the thymus index and spleen index were not significantly different from the control group（P＞0.05）; the villus height, crypt depth and villus height/crypt depth in the duodenum, jejunum and ileum were significantly increased in the experimental group（P＜0.05）. The results suggested that seaweed polysaccharide microelement chelate could significantly improve growth performance, improve intestinal morphology and enhance immune function of weaned piglets compared with glycine microelement chelate.