N-tert -Butoxycarbonyl-methamphetamine ( t -BOCMA), a tert -butoxycarbonyl ( t -BOC) derivative of methamphetamine (MA), which has recently been reported in several countries, was seized for the first time in Japan in 2017. It deprotected easily in an acidic condition to result in an illicit MA, and recently became a newly designated drug of the Pharmaceutical and Medical Device Act. For drug enforcement, the information of its properties was, therefore, strongly demanded. In this study, we synthesized the t -BOCMA standard, acquired various analytical data, and demonstrated its conversion to MA in high yield in the relatively moderate acidic condition (5% HCl methanol solution, 50℃). Also, the stability of t -BOCMA in simulated gastric juice (0.08 M HCl, 37℃) was explored by using GC/MS. As the result, 19% of t -BOCMA remained even after 120 min incubation, and the T_1/2 was calculated to be 50 min. These suggest that the orally ingested t -BOCMA would be absorbed into blood in some degree without conversion to MA.