Based on rainfall observation and daily NCEP/NCAR reanalysis dataset from June t o July in 2005, a comparison of three dimension structures of subtropical high for two regional heavy rainfall events is carried out with characteristic index method and physical diagnosis analysis. The result shows that the subtropical hi gh structure for the two events have different properties, i.e. thermal or dynam ical. This has led to difference for these two events with respect to moisture t ransport condition and large scale background for vertical motion.