Abstract: On the basis of defining a templating index K_t=λ(STA/TPA⁺), where STA/TPA⁺ represents the molar ratio of a secondary templating agent(STA) to tetrapropylammonium cation TPA⁺,λ represents the ratio of the bond length of STA to the bond length of,TPA⁺. The templating indexes for seven common templating agents (amines and alcohols) in the formation of ZSM-5 molecular sieve were determined. It is shown through synthesis experiments that the templating index can quantitatively describe the effect of templating agents.

Key words: ZSM-5 zeolite, templating effect, templating index