Abstract: This experiment was conducted to evaluate effects of sunflower seed oil supplementation on rumen digestion and fatty acid composition. 5 female adult Xuhuai White goats were surgically installed with ruminal fistula. The experiment was divided into two periods by self-control design. Each period lasted for 15 days. Goats were fed a low-concentrate diet in two periods (non sunflower seed oil or 7mL sunflower seed oil per day). Rumen liquid was taken from rumen fistula at the last day of each period. The results showed that the pH value of ruminal liquid was not affected by sunflower oil supplementation. Compared with control period, the concentration of ammonia N, total volatile fatty acid (TVFA), acetate and propionate in the oil supplementation period increased significantly (P<0.05). However, the contents of acetate, propionate and butyrate, the ratio of acetate plus butyrate to propionate ((C2 + C4)/ C3), microbial crude protein (MCP) concentration in ruminal liquid were not affected by the oil supplementation. The concentration of oleic acid (C18:1) and cis9, trans11-conjugated linoleic acid (c9,t11-CLA) in ruminal fluid increased remarkably by sunflower oil supplementation compared with control period (P<0.05). The results implicated that appropriate dose of sunflower oil supplementation could improve rumen digestion and manipulate long chain fatty acid composition in goats fed low-concentrate diet.