By means of conventional meteorological data, the reason s of two extre me high temperature events (clear-and-hot high temperature weather occurred in 1 5 July 2002 and the extreme muggy high temperature weather occurred in 2 August 2002) are studied. The results show that they were controlled by the continental warm high and the subtropical warm high respectively over the western Pacific. Aff ected by topography, they were strengthened by the foehn effect caused by west w ind and the warm moisture accumulation before mountains caused by south wind. So lar radiation is also an important factor causing the extreme clear and hot high temperature event.