Deep　understanding　of　the　formation　mechanism　is　crucial　to　the　rational　design　and　controllable　synthesis　of　zeolites　with　desired　pore　architecture　and　acidity.　Herein,　we　take　the　synthesis　of　NaA　zeolite　from　a　submolten　salt　depolymerized　kaolin　(SMS-K)　as　an　example　to　elucidate　the　formation　mechanism　of　NaA　zeolite.　By　using　SMS-K　as　sole　Si　and　Al　sources,　a　highly　pure　and　crystalline　NaA　zeolite　with　superior　ion　exchange　ability　was　synthesized.　By　using　various　ex-situ　and　in-situ　characterizations　and　studying　the　crystallization　kinetics,　a　plausible　formation　mechanism　of　NaA　zeolite　via　the　mesoscale　reorganization　of　SMS-K　was　proposed.　The　results　indicate　that　the　reorganization　of　SMS-K　into　NaA　zeolite　follows　the　solid-phase　transformation　route.　Upon　being　mixed　with　H2O,　SMS-K　that　is　mainly　composed　of　silicate　monomers　and　chain/ring　microstructures　is　in-situ　transformed　rapidly　into　mesoscale　intermediates　containing　double　four-membered　rings　and　β　cages,　sufficient　stirring　during　aging　generates　more　mesoscale　intermediates.　During　the　subsequent　crystallization　process,　the　mesoscale　intermediates　are　further　self-assembled　into　NaA　nanoparticles　when　theirs　amount　reaches　a　maximum,　and　finally　the　nanoparticles　grow　into　well-shaped　cubic　NaA　zeolite　particles　with　smooth　surfaces　through　layer　spreading.　Our　work　provides　the　theoretical　foundation　for　the　design　and　green　synthesis　of　zeolites　directly　from　the　natural　minerals.　©　2022　Elsevier　B.V.