The formation of organic peroxides in the Cl|atom|initiated photooxidation of CH-4 in O-2|N-2 mixtures at 101 325 Pa and 298 K was studied with HPLC and FT|IR methods. Four peroxidic products were detected, which were H-2O-2, hydroxymethyl hydroperoxide (HOCH-2OOH; HMHP), methyl peroxide (CH-3OOH; MHP) and dimethyl peroxide (CH-3OOCH-3). A chromatogram peak at retention time of 8.08 min was assigned tentatively to peroxyformic acid (HC(O)OOH). The identification of HMHP in the reaction system showed that one of the reaction paths for the self|reaction of CH-3OO· led to producing Criegee intermediate ·CH-2OO·. The formation mechanism of organic peroxide in the photooxidation of CH-4 is more complicated than it was assumed before. Photooxidation of CH-4 is probably an important source of organic peroxides in the troposphere.