3-Isobutyl glutaric acid was synthesized from isovaleraldehyde with ethyl cyanoacetate by the Knoevenagel reaction, and with diethyl malonate by Michael reaction, then by hydrolysis and decarboxylation.Pure 3-isobutylglutaric acid was obtained by purification for the first time, the yield was 71.25%; 3-(carbamoylmethyl)-5-methylhexanoic acid was obtained by 3-isobutylglutaric acid via cyclization and ammonolysis reaction, the yield was 79.88%, 3-(aminomethyl)-5-methylhexanoic acid was obtained from 3-(carbamoylmethyl)-5- methylhexanoic acid via Hofmann reaction, the yield was 79.87%.