The South Asian High variations for the period of 1979 – 2019 are compared based on four sets of definitions. The results show that the location of the South Asian High have an inter-annual variation characteristic, without significant trend and decadal abrupt in the center indices, whereas the intensity and the area index have significant trend and decadal abrupt. When the South Asia high locates more east (west) than usual, the meridional position is southward (northward). When it is stronger (weaker), the area of the South Asian High is larger (smaller). Based on the maximum geopotential height F1 and the closed-circulation-system index F3, the South Asian High intensity is closely connected with the zonal mean value, which indicates that the increasing trend in those two definitions may be forced by the apparent increment of the geopotential height under global warming. However, after removing the parallel circle geopotential height, the significant weakening trends are observed by the eddy geopotential height definition F2 and the changed-isobar closed-circulation-system index F4. The variation characteristics based on F2 and F4 coincide well with those in the eddy geopotential height field and the relative voracity, indicating that removing the uniform rise in geopotential height is more appropriate to present the long-term variation in the South Asian High.