Abstract: The factors affecting the hydrothermal synthesis of molecular sieves with ZSM-12 structure，modification methods as well as application in catalysis are reviewed. A lot of studies show that alkalinity and Si/Al ratio in initial reactive gel are major factors during the synthesis of ZSM-12. Different templates can considerably affect pore dimension，crystal morphology and acidity. Silica gel is the suitable source of silicate. Isomorphic substitution of atoms of crystal framework of ZSM-12 with Ga，Fe，B and P compounds can adjust its acidity. The total amount of acid sites decreases while Lewis acid sites disappear during dealumination of ZSM-12. The catalysts based on ZSM-12 show better catalytic activity and high selectivity in aromatic alkylation，isomerization，cracking，and reforming. It is considered to be the best catalyst for preparing 2,6-dimethylnaphthalene by the shape-selective catalysis one-step method.