The leaching kinetics of roasted clinker with NaOH, which was obtained by roasting potash feldspar with Na2CO3, was studied. The effects of temperature and stirring intensity on the leaching rate of SiO2 were examined. The results showed that under the optimal conditions of leaching temperature 95℃, stirring intensity 400 r/min, clinker granularity 74~89 mm, NaOH concentration 0.2 mol/L, and leaching time 80 min, the leaching rate of SiO2 reached up to 99%. The leaching process of roasted clinker was mixed controlled by the chemical reaction and external diffusion without the solid product layer. The leaching process included the earlier stage in 0~10 min and the later stage during 10~80 min. The apparent activation energy of two stages was 15.24 and 29.94 kJ/mol, respectively. The kinetic equations could be expressed as 1-(1-a)1/3=7.074exp[-15239/(RT)]t and 1-(1-a)1/3= 45.85exp[-29940/(RT)]t, respectively.