In this study, Halloumi cheese samples were produced from preacidified cow's milk. Glucono-delta-lactone (gdl), lactic, citric and acetic acids were used in preacidification treatments. The cheese samples were vacuum packed and ripened at 7±1°C for 90 days. The changes in some chemical, microbiological and sensory properties of the Halloumi cheese samples were investigated during the ripening period. Gall and lactic acid were found more suitable than citric and acetic acids as an acidulant in Halloumi cheese production.