Synthesis NaY zeolite using natural kaolin (Si/Al ratio∼ 1) as an alternative source for silica and alumina is still challlenging. The aims of this study is to find out an effective and enviromentally friendly route to synthesis NaY zeolite from different source of silica and alumina. Pre-treatment kaolin like purification and fragmentation were conducted in order to reducing major impurity in kaolin such as quartz. Activation kaolin by Sub-Molten Salt System (SMS) using NaOH was employed because structure of Si-O and Al-O are inert and inactive. The kaolin was produced then used to synthesis NaY zeolite through hydrothermal method with a seeding technique using the mole ratio of (seed gel (5% of Al): 10, 67Na 2 O: Al 2 O 3: 10SiO 2: 180H 2 O)[1]. In order to find out optimum condition, the variation of crystallization time was performed. By the various characterization technique, the experimental result reported that NaY zeolite has the structure with mesoporous pore 3.6 nm and Si/Al ratio 3.8.