Abstract: Objective To explore the prevention and treatment effect of Saccharomyces boulardii on hyperlipidemia. Methods Forty SD rats of SPF level were randomly divided into four groups (10 rats in each group). Group A was given normal diet. Group B was given high fat diet. Group C was given Saccharomyces boulardii powder after 70 days besides high fat diet. Group D was given Saccharomyces boulardii powder from the beginning besides high fat diet. The blood of rats in 4 groups were collected for testing TC, TG, LDL-C, HDL-C on day 1, day 70 and day 112. Results On day 70, the serum TC (group B: 2.39±0.21 vs 1.93±0.15, group C: 2.45±0.29 vs 1.94±0.24), TG (group B: 1.04±0.21 vs 0.74±0.13, group C: 1.02±0.18 vs 0.76±0.15), LDL-C (group B: 1.04±0.12 vs 0.46±0.12, group C: 1.06±0.16 vs 0.46±0.07) of group B and group C were higher than day 1 (P< 0.01). The serum TC of group D on day 70 had no change compared with day 1 (2.05±0.14 vs 1.98±0.21, P> 0.05), while TG decreased (0.53±0.12 vs 0.77±0.22, P< 0.05). LDL-C was higher than day 1 (0.74±0.15 vs 0.48±0.09), but it was still lower than that in group B (0.74±0.15 vs 1.04±0.12, P< 0.05) and group C (0.74±0.15 vs 1.06±0.16, P< 0.05). On day 112, the serum TC (2.13±0.19 vs 2.45±0.29), TG (0.46±0.07 vs 1.02±0.18), LDL-C (0.56±0.16 vs 0.81±0.11) of group C were lower than that on day 70 and in group B (2.13±0.19 vs 2.60±0.18, 0.46±0.07 vs 1.06±0.22, 0.56±0.16 vs 0.72±0.09, P< 0.01). Conclusion High fat feedstuff can increase rats' blood lipid significantly. Saccharomyces boulardii has preventive effect on the formation of hyperlipidemia.