This paper deals with the study of moisture budget of the typhoon No.7507. The results show that the mass convergence produced by divergent wind has made the maximum contribution to precipitation, especially at the lower level, accounting for about 70% of the total precipitation, and that the advection term of water vapor is very small. The vertical flux term is to transport water vapor from the lower level to the middle and upper levels, resulting in the increase of water vapor accumulation at these levels. Evaporation term also plays an important role in precipitation, accounting for about 13% of the total precipitation and 23% of the horizontal moisture convergence. The moisture of the typhoon comes mainly from its southern boundary and the secondary inflow of moisture is from its western or eastern boundary. All the inflow layers of these three boundaries are very deep, reaching up to 300 hPa, while the strongest inflow occurs below 700 hPa. In the northern boundary of the typhoon, we obtained that all layers had the outflow of moisture. As to the whole typhoon system,since the inflow of water vapor is far greater than the outflow, a large amount of water vapor might be supplied for the typhoon. The distrioutions of precipitation in the typhoon region by using three computational methods are in good accordance with the actual distributions of cloud and rain areas, but there exists marked difference in magnitude.
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