Abstract: The effect of calcination temperature, washing times and ammonium salt concentration on the sodium content and the microactivity (MAT) of the catalytic catalyst was studied. The catalysts with different sodium content were prepared by using zeolites with different sodium content. The sodium oxide in the catalysts was removed by post-treatment of calcination and ammonium salt washing. The results reveal that the sodium contents of the catalysts remain stable with the increase of calcination temperature under the same washing conditions when the calcination temperature is lower than 450 ℃. The same results are also for the catalysts washed with different concentration of ammonium sulfate at fixed calcinations temperature. But twice calcinations and washing can reduce the sodium oxide content of the catalysts to the level of industry catalyst. Small changes of MAT are observed for the catalysts washed by ammonium salt and calcinated between 300℃ and 400℃. As the calcination temperature increases to 500 ℃ or even higher, both of specific surface area and activity are significantly decreased. An empirical formula between catalyst activity and sodium content is established for prediction of catalyst performance.