Abstract: The biweekly mechanism of east-west oscillating movement of the subtropical western Pacific high is studied using the dynamic method. The result shows that the circulation conditions for East Asia is such that the synoptic biweekly CISK-wave can be initiated by thermal forcing due to latent heat condensation from monsoon rain in continental East Asia and tropical rain in the South China Sea and western Pacific. There are what it is called "self-adjusting" effect in the wave kinetc energy in its dispersive variation towards the subtropical East Asia continent, resulting in extension and/or retreat of the subtropical high in the western Pacific.