Abstract: In this paper, two empirical equations, I = 6 (T +100) t_{1^00.0035T and I = 398.15(t2 - 0.8)^-0.06lg11T, were suggested to express the correlation between the intensity ( I ) of Na²³-NMR spectrum, which is proportional to the number of Na⁺ in crystal lattice of Xtype zeolite, aging time (t1) and the time (t2) of complete crystallization of "directing-agent" at different temperature. On the basis of these results, a kinetic model of crystal growth of NaY type zeolite in presence of so-called directing-agent was suggested, and the mechanism of the "directing-agent" effect has been characterized.}