The number of persons arrested in Japan for drug-related offenses in 2016 increased from the previous year. Especially, cannabis offenses have increased since 2014, with more than 2000 persons arrested in 2015. As a feature of the year 2017, we analyzed many cannabis concentrates, called “Cannabis wax”, in the process of analyzing cannabis in the Narcotics Control Department. “Cannabis wax” refers to concentrates of the hallucinogenic component of cannabis, tetrahydrocannabinol (THC). Increasingly, cannabis wax containing 50 times higher THC than general dry cannabis has been confiscated. More than 2300 compounds are currently regulated as new psychoactive substances in Japan. In a recent trend, there is an increasing number of cases in which a wide range of regulated substances have been seized and confiscated, ranging from those that have been abused for a long time, to those that are newly regulated. Many structural isomers are present among these, and we are constantly developing techniques for the rapid and accurate analysis of these compounds.