Abstract: The maintenance mechanism of two kinds of blocking highs is studied. The results show that the distribution regimes of mean flow transfer of quasi-geostrophic potential vorticity and transient disturbance flow transfer for two kinds of blocking highs are different, and their maintenance mechanism would be different too. The transient disturbance fields of two kinds of blocking highs in diffluent regions appear to be elongate in the north-south direction. This kind of deformation plays an important role in the maintenance of blocking high.It is also shown that the synoptic scale disturbance would reduce its scale in the process of eastward movement, when energy transformation obeys the bidirectional transformation principle, a lot of disturbed kinetic energy would transfer to mean fields, and so, blocking high could be maintained.