OBJECTIVE To investigate the absorption characteristics and tissue distribution of silybin （Sy） nanocrystals prepared by two methods in different intestinal segments of rats. METHODS Sy nanocrystals （i.e. Sy-NS-G and Sy-NS-F） with comparable particle sizes were prepared using high-pressure homogenization and anti-solvent precipitation methods， respectively. Rats were randomly divided into three groups： Sy raw drug group， Sy-NS-G group， and Sy-NS-F group. Each group was further divided into three subgroups with low， medium， and high （60， 120， 180 μg/mL） mass concentrations （calculated based on Sy）， with 3 rats in each subgroup. The absorption rate constant （Ka） and apparent absorption coefficient （Papp） of Sy raw drug， Sy-NS-G and Sy-NS-F in different intestinal segments were investigated by using the in vivo one-way intestinal perfusion experiment. Additionally， the rats were divided into three groups: Sy raw drug group， Sy-NS-G group， and Sy-NS-F group， with 20 rats in each group. Rats in each group were administered a single intragastric dose of 50 mg/kg （calculated based on Sy）. They were sacrificed at 0.3， 1， 4， 10， and 24 hours post-administration respectively， to investigate the tissue distribution of Sy raw drug， Sy- NS-G， and Sy-NS-F in the heart， liver， spleen， lungs， kidneys， brain and intestines. RESULTS In duodenum and jejunum， the Ka and Papp of the nanocrystals prepared by the two methods remained unchanged with the increase of Sy concentration， and there was no significant difference （P＞0.05）； the absorption of Sy-NS-F in the duodenum was greater than that of Sy-NS-G； the absorption sites of Sy-NS-G and Sy raw drug were mainly in the ileum， while those of Sy-NS-F were mainly in the duodenum and ileum. The concentrations of Sy-NS-G and Sy-NS-F in different tissues of rats were different； Sy-NS-G peaked in most tissues at 1 h， and the distribution concentration was as follows： intestine＞spleen＞heart＞lungs＞liver≈brain＞kidneys. Sy-NS-F reached its peak at 1 h， and the distribution concentration was in the order of intestine＞spleen＞kidney＞lung＞heart≈liver＞brain. CONCLUSIONS The absorption mode of Sy nanocrystals in the duodenum and ileum is mainly passive diffusion. In the duodenum， the absorption of Sy-NS-F is greater than that of Sy-NS-G； there are significant differences in the tissue distribution of Sy-NS-G and Sy-NS-F in rats.