Abstract: The aim of this study was to determine the anti-obesity effect of chitosan and curcumin at their single and combined formulation on normal and obese rats, and further clarify the mechanism of action.For the body weight inhibition study, five groups of 10 young male rats were given intragastrically with water, chitosan, curcumin, low and high dosage of the combined drugs, feeding with high-fat diet, for nine weeks.Body weight, blood fat, the amount of faeces and their lipid content were measured at the end to evaluate the body weight increase inhibition effect of drugs.The weight increase inhibition had been significantly found in the CH +CU groups since 3 weeks.Food intake was similar in all five groups.Faeces and Faecal lipid were significantly higher in the CH+CU groups while blood fat was lower.For the anti-obesity study, obese rat got by feeding high fat diet were divided randomly into 5 groups and given intragastrically with same drugs for 4 weeks.The weight decrease, blood fat and fat tissue content were test at the end of test.Under both chitosan and curcumin possess trifle anti-obesity effect, the CH +CU had best effect, and high dose has better effect than the low dose.It could be concluded that chitosan and curcumin had better anti-obesity effect at the combined formulation using.