The study aimed to explore the effects of Pediococcus pentosaceus 368 on Archaea and metabolites in feces of Duroc×Saba pig. Twenty Duroc×Saba pigs which body weight were about 77 kg were randomly divided into 2 groups with 10 pigs per group. The pigs in experimental group drinked water added with Pediococcus pentosaceus 368（10¹⁰ CFU·L^-1）. The experiment lasted for 28 days. On the day at the end of the experiment， slaughterings were conducted. The effects of Pediococcus pentosaceus 368 on Duroc×Saba pig were analyzed through the Archaea in feces and the fecal metabolites. The results showed as follows： 1） PCoA （Principal Coordinates Analysis） analysis found that samples in the experimental group and control group could not be completely separated， and species similarity in the experimental group became consistent after the addition of Pediococcus pentosus 368.2） At the phylum level， the highest relative abundance of the two groups was the Candidatus_Thorarchaeota and at the genus level， the highest relative abundance of the two groups was Methanobrevibacter. When the Linear Discriminant Analysis value was highter than 3.0， the two groups obtained 14 biomarkers. Among them， 14 biomarkers were in the experimental group， and the largest LDA value in the experimental group was the Thermoplasmata_unclassified.3） KEEG metabolic pathway analysis found that when the LDA value was highter than 3.0， the functions of 4 genes were screened out： Folding_sorting_and_degradation， membrane transport，Cell motility and Signal transduction； Analysis of the level function of CAZy （Carbohydrate Active enzyme Database） showed that when the LDA value was highter than 3.0， a total of 21 biomarkers were obtained in the two groups， of which 13 were in the experimental group. The biomarker with the largest LDA value in the experimental group was CBM20. In the control group， the biomarker with the largest LDA value was GT2.4） Fecal short-chain fatty acid analysis showed that the contents of Butyric acid and Isovaleric acid in the experimental group were significantly decreased （P<0.05）. 5） KEGG pathway enrichment analysis of differential metabolites found that there were 12 significantly different terms， which were as follows： Degradation of flavonoids，Linoleic acid metabolism， Cutin， suberine and wax biosynthesis， Arginine biosynthesis， Valine， leucine and isoleucine biosynthesis， Retrograde endocannabinoid signaling， Biosynthesis of phenylpropanoids，Biosynthesis of unsaturated fatty acids， Autophagy-animal， Fatty acid biosynthesis，Kaposi sarcoma-associated herpesvirus infection； Gene Set Enrichment Analysis （GSEA） identified three significant genes： Glycerophosphates metabolism； Glycine， serine and threonine metabolism； and Biosynthesis of unsaturated fatty acids. （Conclusion） In summary， the addition of Pediococcus pentosaceus 368 can make the species similarity become consistent in the fecal Archaea of Duroc×Saba pigs. Improve the relative abundance of microbial functional genes related to Signal transduction， Cell motility， amino acid and fat metabolism in feces， and improve the probiotic function of bacteria and enzymes related to amino acid and fat metabolism.