BACKGROUND: Suppressor of cytokine signaling-1 and -3 (SOCS-1 and SOCS-3) are two important negative regulators in the insulin-signaling pathway, and their overexpression may aggravate insulin resistance. Subjects with insulin resistance are often obese and have increased expressions of SOCS-1 and SOCS-3. We speculated that SOCS-1 and SOCS-3 may be involved in abnormal deposition of adipose tissues during insulin resistance. METHODS: A catch-up growth intrauterine growth retardation (CG-IUGR) rat model with insulin resistance was established; mRNA and protein expression of SOCS-1, SOCS-3, the CCAAT/enhancer binding protein (C/EBP alpha), and peroxisome proliferator-activated receptor (PPAR gamma) in adipose tissue were measured by real-time PCR and western blot; plasmids carrying small hairpin RNAs (shRNAs) targeting the SOCS-1 and SOCS-3 genes were constructed and transfected into preadipocytes, which were then induced to mature. At 72 h after differentiation was induced, the expressions of C/EBPa and PPAR gamma, two important molecules promoting the differentiation of preadipocytes, were detected. RESULTS: Expressions of SOCS-1, SOCS-3, C/EBP alpha, and PPAR gamma were markedly increased in adipose tissues of CG-IUGR rats, whereas the expressions of C/EBP alpha and PPAR gamma were significantly reduced after gene silencing of SOCS-1 or SOCS-3 in adipocytes. CONCLUSION: Overexpression of SOCS-1 and SOCS-3 may enhance the expression of C/EBP alpha and PPAR gamma, resulting in abnormal deposition of adipose tissues during insulin resistance.