The photochemical reaction of aqueous ethanol saturated with argon and carbon monoxide has been investigated using 184.9 nm UV light. The photochemical reaction of $1{ imes}10^{-2}$ M aqueous ethanol saturated with argon results in the formation on the acetaldehyde and 2,3-butanediol. The irradiation of the solution saturated with carbon monoxide causes the formation of carbonylation and carboxylation products such as ${alpha}$-hydroxypropionaldehyde, formaldehyde, glyoxal, formic acid, oxalic acid and glyoxylic acid in addition to above two products. But in the case of concentrated ethanol solutions, the irradiation did not give carbonylation and carboxylation products. The initial quantum yields of the products were determined and probable mechanisms for the reaction were presented on the basis of product analysis.