Solid surface enhancement effects on chemiluminescence (CL) have been studied using alkaline metal salts as solid media. Effects of number of cationic species (alkali metal ions: Na+ and K+ ions) on chemiluminescence of diaryl oxalate type CL reagent were investigated. It was found that sodium and potassium ions are the most active CL enhancers among alkaline metal ions, and the more sodium ions (or potassium ions) are included in the solid medium, the stronger the CL intensity.