A series of aromatic ring-modified praziquantel derivatives were prepared and evaluated against juvenile and adult stage of Schistosoma japonicumin. Several analogs comparable in activity to the drug praziquantel have been identified based on in vitro and in vivo japonuicum schistosomes worm viability assay. Structure and activity relationship of these praziquantel aromatic ring-modified compounds was revealed. Specifically, a compound in which a bromine has been introduced in the aromatic ring of praziquantel demonstrated close antischistosomal activity to praziquantel in vivo.