Abstract: Extracts from Dunaliella Salina (EDS) is a kind of fat-soluble mixture extraced from the allopelagic dunaliella salina. It contains vitamin E and unsaturated fatty acid besides large quantity of carotenoid. We observed the effect on death rate and inhibition rate to cancerous ( S₃₇) rats with EDS therapy for one month. The results of two batches were similar: the inhibition rate in the group of high dosage was 10.97%, 11.7% and in the group of low dosage was 12.53%, 18.5%, Both the in-hibition rates were better than that in group BC (Betacarotene), but were lower than that in Cyclophosphamide group. The death rate was 10% in group of blank control and none of the EDS group was dead.