The object of the present invention is to produce cycloalkanol and/or
cycloalkanone with good selectivity by oxidizing cycloalkane with
molecular oxygen. The method of the present invention contains the step
of oxidizing cycloalkane with molecular oxygen in the presence of cobalt
salt of carboxylic acid and cobalt complex with porphyrin as a ligand,
the cobalt complex with porphyrin as a ligand being a compound
represented by the formula (1): ##STR00001## wherein each of X.sup.1
to X.sup.8 independently represents a hydrogen atom, a halogen atom, a
nitro group, a cyano group, a hydrocarbon group, a halogenated
hydrocarbon group or a sulfonyl group, and each of R.sup.1 to R.sup.4
independently represents a hydrogen atom, a nitro group, a cyano group, a
hydrocarbon group or a halogenated hydrocarbon group.