This study was conducted to investigate the effects of aflatoxin B₁ (AFB1) on growth performance, liver tissue and intestine health of weaned piglets. Thirty-two 21-day old Duroc×Large White×Landrace weaned piglets with similar parity and body weight were randomly divided into two groups with 16 replicates per group and 1 pig per replicate. Pigs in the two groups were fed the basic diet with or without 0.3 mg/kg AFB1 respectively for 21 days after 3 days adaption with free feeding and drinking. At the end of the experiment, all piglets were weighed on fasting condition and 6 pigs in each group with similar average body weight were selected to collect the samples for measuring the growth performance, liver healthy, intestinal mucosa morphology and intestinal microflora amounts. The results showed as follows:compared to control group, diet with AFB1 significantly decreased the average daily gain (P<0.05), while significantly increased the ratio of feed to gain (P<0.05) and tended to decrease the average daily feed intake (P=0.09) of weaned piglets. Diet with AFB1 significantly increased the liver index (P<0.05) and induced unsharp structure of liver lobule, moderate hydropic degeneration of hepatocytes and partly medium and heavy focal necrosis, meanwhile obvious hyperplasia of hepatic fibrosis of weaned piglets. Diet with AFB1 had no significant effect on the mRNA expression of lipometabolism-related genes including acetyl coenzyme A carboxylase-1, fatty acid synthase, carnitine palmityltransferase-1, lipoprotein lipase and peroxisome proliferators activate receptor-α in the liver (P>0.05). Diet with AFB1 significantly increased the villus height and crypt depth of duodenum and decreased the crypt depth of jejunum (P<0.05). Diet wtih AFB1 significantly reduced the Bifidobacterium amount in cecum (P<0.05), but had no significant effects on the amounts of total bacteria, Escherichia coli, Lactobacillus and Bacillus (P>0.05). In conclusion, it is suggested that diet with 0.3 mg/kg AFB1 can decrease the growth performance and cause slight impairment of liver histology and intestine health of weaned piglets, and the underlying mechanism remains to be further studied.