Taking the affinity between events and media as a conceptualization base, a total of 1032 related news re-ports of Expo '99 Kunming, gathered from the internet data bank of China INFOBANK from 1992 to 2003, are used as data sources. After classifying them with a communication research method-the content analysis, a data bank for SPSS is set up, and a mathematic model called the Integrated Impact Index of Expo '99 Kunming is constituted. With the model, the spatial distribution of the total integrated impacts of Expo '99 Kunming on the regions or cities with different regional scales is analysed quantitatively. The conclusions are: 1) the Expo '99 Kunming made obvious integrated impacts on the regions or cities of every scale, especially in the venue city and the region-Kunming City and Yunnan Province; 2) it had corresponding impacts on other provinces; 3) the spatial distribution of Integrated Impact Index had a disaggregation with both plane extension and spotted decentralization; and 4) there was a distance decay law in all three scales of regions (Kunming City, Yunnan Province and the whole China), which incarnated the spatial extension law of the integrated impact of a special mega-event.
