Abstract: Isothermal phase transformation digram was developed for the K₂O-Na₂O-Al₂O₃-SiO₂-H₂Osystem at 100℃. T-type zeolite was obtained as a pure phase from the reaction mixture with the mole ratio as. 32>SiO₂/Al₂O₃>24 0.34>M₂O/SiO₂>0.30 0.30>K₂O/M₂O>0.23 H₂O/SiO₂ = 16 In the induction period of T-type zeolite or amorphous phase region there were no spontaneous nucleation. Akinetic model on the crystal growth of rod-like T-type zeolite was suggested as dx/dt= k_x^2/3 , where k is related to the composition of original gel, especially to the temperature. E_c of T-type zeolite was measured as 16.7Kcal/mol for the system of 1.95K₂O·5.85Na₂O·Al₂O₃·26SiO₂·416H₂O.