The meteorological conditions for a heat balloon flying over the Taishan mountain and the effect of the mountain of a heat balloon flying were discussed. By using historical data from Sep. to Oct. during 1988 to 1995,the meteorological conditions fitting the operation of a heat balloon flying were analysed. According to the weather situation and the characteristic that a heat balloon flying over the Taishan mountain was effected by many elements,some factors of better relativity among the elements were selected,and the forecast equations were established respectively,and then the synthetic forecast was given.