The present study aimed to investigate the effects of administration of Capparis spinosa (CS) fruit aqueous extract on liver metabolism in streptozotocin (STZ)-induced diabetic rats. The aqueous extract of CS was orally administered at a dose of 20mg/kg for 28 consecutive days and then its effects on blood glucose, lipid and insulin levels in normal and STZ diabetic rats were comparatively investigated. Furthermore, the effects of CS on the activity and expression of the key enzymes of gluconeogenesis and hepatic lipid content were investigated. The results showed that administration of CS extract in the STZ diabetic rats significantly decreased blood glucose level, while no significant influence on the insulin level. In addition, CS significantly decreased blood and liver triglyceride and cholesterol content in STZ diabetic rats. Furthermore, CS administration significantly reduced the mRNA expression and enzyme activities of glucose-6- phosphatase and phosphoenolpyruvate carboxykinase in liver tissues. Our findings demonstrated the beneficial effects of CS on blood glucose and lipid levels in an insulin- independent manner. This study also showed that CS improved the circulating levels of triglyceride and cholesterol. In addition, direct inhibition of gluconeogenesis in liver may be a probable mechanism of action of this plant. Since CS also decreased liver lipid content, we suggest that CS administration might be a beneficial therapeutic approach for metabolic syndrome and fatty liver.