AIM: To evaluate the safety of Curcuma aromatica oilgelatin microspheres (CAO-GMS) infused via hepatic artery against primary liver cancer.METHODS: The safety of CAO-GMS was evaluated in view of its acute toxicity in rats, long-term toxicity in Beagle dogs and general pharmacology in rats and mongrel dogs. RESULTS: The 50% lethal dose (LD50) of CAO-GMS infusedvia the hepatic artery was 17.19 mg/kg, and the serum biochemical indices of dying rats after the administration changed markedly while those of survived rats did not. Subsequent pathological examination of the tissues from the dead rats indicated improper embolism. Similar edema and small necrotic foci in the hepatic Iobule were found in the hepatic tissue of rats receiving 10 and 5 mg/kg CAO GMS and GMS 60 d after the last administration, while not in the rats of the blank control group, indicating that microspheres infused via the hepatic artery may induce irreversible liver damage dose-dependently. General pharmacological study showed that the activities (postureand gait), respiration frequency, blood pressure or heart rate of the dogs were not affected by CAO-GMS, nor were salivation, tremor or pupil changes of the rats observed or their balancing ability compromised, suggesting CAO-GMSinfused via the hepatic artery did not significantly affect the nervous, respiratory and cardiovascular systems. CONCLUSION: CAO-GMS embolization administered via the hepatic artery is safe but undesired embolization induced by vascular variation should be given due attention in its clinical application. Individualized embolization dosage and super-selective catheterization technique are recommended to avoid undesired embolism and reduce complications.