With the use of two new oximes that have just recently made debut, namely, diacetylmonoxime (DAM) and monoisonitroscacetone (MINA), the author made comparative study of their effectiveness on alkylphosphate poisoning with that of pyridine-2-aldoxime methiodide (PAM). Alkylphosphates used in the present experiment were commercially available ones such as Ethyl- and Methylparathion EPN, TEPP, Pestox-3, Malathon, Daizinon, Dipterex and DFP. 1. LD(50) of DAM given intravenously to mice is 356 (337-376) mg/kg, and that of MINA is 159 (133-191) mg/kg. 2. In determinig LD(50) of various alkylphosphates excluding DFP by injecting intravenously 80 mg/kg DAM or 40 mg/kg MINA, there can be found no difference from the control group of mice given only alkylphosphates. 3. After injecting intravenously 100 mg/kg DAM or 30 mg/kg MINA into rabbits and observing the effects of these drugs on the serum cholinesterase activity that has been inhibited by various alkylphosphates, DAM is slightly effective in the case of Malathon and DFP poisoning while MINA on EPN, TEPP, Diazinon, and DFP, but the effect of either one is quite inferior to that of PAM. From these results the effects of DAM and MINA on the alkylphosphates mentioned above are quite disappointing, and their effects at leaet can never be said to exceed that of PAM.