Abstract: From 1984-1987, mass application of mebendazole-medicated salt was studied for the control of hookworm infection in 5 pilot areas (Wuming, Shanlin, Bobai, Guilin and Rongxian Counties) in Guangxi Zhuang Autonomous Region. The dosages of me-bendazole (mixed with salt) administered were 15mg, 25mg, 30mg, 40mg, 50mg, 60mg, 70mg, 80mg, l00mg or 200mg per person per day for 15, 20 or 30 days. The results showed that 40mg/day for 15-20 days could result in stool egg negative conversion rates of 92.3 to 94.4%, while 50mg/day for 30 days resulted in 96.9 to 100%. Con-currently, the hookworm infection rate in pilot areas dropped by 57.9-71.7% in a short time; whereas the stool egg negative conversion rate of Ascaris lumbricoides was as high as 99.1% to 100% at the same dosage, when the dosage of 100mg/day for 30 days was given, the egg negative reversion rate for Trichuris trichiura was 97.6%. Promising result was also recordcd concerning the tolerance of the medicated salt, as the side effects in the inhabitants were mild.In conclusion, the authors considered that the application of mebendazole-medicated salt was a simple and effective measure in controlling hookworm infection, especially in the light of solving the problem of incomplete mass detection and selected mass treat-ment. Furthermore, it is much more economic from the cost-effect point of view.