As a part of our studies on the structure-activity relationship of 1, 3-disubstituted 5-dialkylamino-6-methyluracil derivatives, we have synthesized 1, 3-disubstituted 5-dialkylaminomethyl-6-methyluracils (B). In the synthesis, 1, 3-disubstituted 5-cyano-uracils (1-6) were hydrogenated with Raney-cobalt followed by methylation to give the 5-dimethylaminomethyluracil compounds (16-20). The Mannich reaction of 1, 3-disubstituted uracils (23-26, 33) did not proceed, but halogenomethylation of them and subsequent amination gave the 5-dialkylaminomethyl compounds (20, 34-41). As to their pharmacological activities, analgetic, antipyretic and antiinflammatory activities and acute toxicity were tested. The compounds (B) showed only antiinflammatory activity.