1. Neutron acivation analysis of arsenic contained in Korean human liver was studied in the view point of forensic chemistry, using 12 corpses. A sample of 1g was irradiated for 30 mins. in a neutron flux of 1.2×10^(12)n/㎠/sec, followed by nitric-sulfuric acid digestion and then by Gutzeit separation. Radio activity was detected by it`s scintillation counter. The arsenic content in the liver was found to be 0.01㎍/g to 0.15㎍/g. 2. A rapid and convenient method for the radiochemical determination of minerals by neutron activation analysis was established. After neutron irradiation to the standard soln.of Cu and Mn in pneumatic tube (neutron flux : 1.2×10^(12)n/㎠/sec), Cu and Mn were determined by estimating the ratio of the widths under energy peak area in γ-ray-spectrogram. When the standard soln. of Mn and Cu is irradiated for 15 mins. to 18 hrs., recovery test shows that the relative errors are 5.1% and 4.5% for copper and manganese, respectively.