Go-doping of lithium (Li) and iodine (I) in ZnSe was studied with metalorganic vapor-phase epitaxy, Since Li has the well-known metastability of substitutional acceptor sites and interstitial donor sites, the examination of the stability of Li sites will be effective to study the co-doping effect. Although the ZnSe films doped with Li showed photomuninescence (PL) spectra dominated by neutral-donor-bound excitons at 13 K, the PL spectra showed the systematic shift to the neutral-acceptor-bound excitons by co-doping with I doping. The corresponding turn-over of the electrical properties from n- to p-type was also observed.