Two new as -cast alloys based on high copper Al-Cu15-Mg-Ti system were developed. The microstructure of the Al-Cu15-Mg-Ti alloys mainly consists of c( -Al, Al2Cu and Al2CuMg phases. In this paper, the structure of eutectic Al2Cu and Al2CuMg phases in Al-Cu15-Mg-Ti system has been determined by using a high-resolution electron microscopy. The Al-Cu 15-Mgt-Ti and Al-Cul5-Mg5-Ti alloys had similar microstructures that consisted of et -Al grains and eutectic structure. With the increase in eutectic fraction the hardness and strength of AlCul5-Mg-Ti alloys increased.