Abstract: Nine N-substituted-3-halo-mesidines have been synthesized for the purpose of testing their activities against Schistosomiasis japonica in experimentally infected animals. They were synthesized by the condensation of 3-halo-mesidines with substituted aminoethyl chloride.The 3-halogenated mesidines were obtained from mesitylene via nuclear dinitration,partial reduction to nitro-amines,diazotization to introduce a halogen group,and reduction of the remaining itro group. The halogenated mesidines synthesized by the above route were of superior yield to those ob- tained by other methods such as monohalogenation,nitration,and reduction,or mononitration, reduction,and direct halogenation.