Abstract: To search for an effective anthelmintic for mass treatment of Clonorchis sinensis, Ascaris lumbricoides, hookworm and Trichuris trichiura infections, a program was conducted to eva luate the effect of albendazole medicated salt during 1992-1993 in Lianping County, Guangdong. The medicated salt contained 1% albendazole. A total dose of albendazole 5 g in 500 g of medicated salt was administered in a period of 30 d. The egg negative conversion rate in 45 inhabitants infected with C. sinensis was found to be 91.1% a month after cessation of the medication; while the rates for persons infected with A. lumbricoides (78), hookworm (29) and T. trichiura (49) were 100%, 96.7% and 98.0%, respectively, upon using 2.5 g and assessed 2 wk post completion of the course of 15 d. The side effects of the medicated salt were mild and self limited, neither were there any changes in blood picture, urinalysis, liver function, ECG, or in ultrasonography.