OBJECTIVE To observe the effects of soothing liver and invigorating spleen recipes on NF-kappaB signal pathway related genes and proteins in primary hepatocytes of rats with NASH. METHODS SD male rats were randomly divided into 8 groups: normal, model, high/low-dose soothing liver group, high/low-dose invigorating spleen group, high/low-dose integrated group. 15 rats in each group. The NASH model rats were induced by feeding high-fat diet (HFD). The treatment lasted for 16 weeks. Then TC, TG in the liver tissue and serum were determined with automatic biochemical analyzer. HE staining and oil red O staining were operated to observe the pathological changes. Another 6 rats of each group were taken respectively and collagenase (Type IV) was perfused to digest liver tissue with the circulation in vitro to separate hepatocytes. The expression levels of IKK(beta), NF-kappaB mRNA, proteins and phosphorylated IKK(beta) protein in hepatocytes of rats from each group were detected by Real-time Q-PCR and Western Blotting, respectively. RESULTS Compared with normal group, liver histopathology was changed and levels of TC and TG were elevated in model group indicating hepatocytes had lipid accumulation and lipid metabolic disturbance obviously; The levels of serum TC, and hepatic homogenate TC, TG as well as the expression of IKK(beta) NF-kappa-B mRNA, proteins and phosphorylated IKK(beta) protein in hepatocytes were dramatically increased in model group (P < 0.01). Compared with the model group, the levels of IKK(beta), NF-kappaB mRNA expression were decreased most significanly in the invigorating spleen (with high dose) group and the integrated group (with high dose) (P < 0.01 or P < 0.05). The expression levels of the IKK(beta), NF-kappaB proteins and the phosphorylated IKK(beta) protein in hepatocytes were decreased significaniy in the treatment groups (P < 0.01 or P < 0.05), especially for the invigorating spleen (with high dose) group and the integrated (with high dose). CONCLUSION Soothing liver and invigorating spleen recipes have effect on NASH rats induced by HFD and its mechanism may be related to the suppression of IKK(beta)/NF-kappaB signal pathway related genes and proteins. And the effect probably has a dose response relationship.