[ Objective] To profile the differentially expressed genes in small intestine between piglets with intrauterine growth restriction (IUGR), describe the relationships between growth performance and gene expression in IUGR piglets, and thus provide a theoretical basis for further research. [Metbed] Eight suckling piglets at the age of 21 d Efour with normal body weight (NBW) of (1 503 ± 310) g and four with low BW of (806 ±35) g] were killed, and the intestinal samples were collected. Gene expression was detected by Affymetrix Porcine GeneChip and further confirmed by quantitative real-time PCR. [ ReseltJ Microarray analysis showed that there were 156 differentially expressed genes in the small intestine between the IUGR piglets and the age-matched NBW piglets, including 61 down-regulated genes and 95 up-regulated genes, The up-regulated genes included protein tyrosine phosphatase, myosin, troponin, heat shock protein, metallothionein, arginine vasopressin-induced 1, ribosomal protein L6, apoptosls antagonizing transcription factor, muscle creatine kinase, mannosidase, lysozyme, folliculin, urate transporterchannel protein, pyrroline-5-carboxylate reductese-like, and adenine phosphor-dbosyltransferase. The down-regulated genes included protein kinase, arachidohate 12-1ipoxygenase, transcription factor A, GTP-GDP dissociation stimulator 1, serine (or cysteine) proteinase inhibitor, fetuin, dolichol-phosphate-mannose synthase, apolipoprotein H, argininosuccinate synthetase 1, iron-regulated transporter, alpha-2-macroglobulin, immunoglobulin superfamily, thioltransferase, and guanylate binding protein 2. The gene expression profile changed in the small intestine of piglets with intrauterine growth restriction, providing a theoretical basis for eady intervention in growth restriction.