A comparative study has been made of 5-methyl-1,2,3-cyclohexanetrionetrioxime with nioxime and din~ethylglyoxime; complexes with nickel, copper, and cobalt have been investigated. Dissociation constants of the three reagents, in aqueous solution, have been determined and formation constants of their copper complexes evaluated. Spectrophotornetric and potentiometric studies were used to obtain the results.