A direct-chill (DC) cast process of an aluminum ingot of size 3200×1292×320 mm3 isanalyzed numerically by the analysis of a fixed controlled system. The study investigates the DCprocesses in which liquid aluminum is cooling continuously in mold and then with water spray atthe exit of mold. An inverse method is applied to measure heat transfer coefficient on watercooling surface experimentally. A correlation of heat transfer coefficient with surfacetemperature is used in numerical simulation. It has been approved that the defected curl and tearsare caused by the higher rates of initial cooling and solidifying in mold and the sweat andliquation are caused by the isolation of heat transfer by air gap formed between cast solid surfaceand the mold wall by volume shrinkage with solidification. The present research analyzes thevariations of temperature profiles in the cast ingot by the changes of cast speed and casttemperature and assesses the improvements of mold and cast process for the better cast quality.