Abstract: This paper studies spatial-temporal features of its integrated impact index (III) by using the Content Analysis Method (CAM), the concept of the information entropy measurement (Hartley) and statistical analysis through SPSS. The fundamental data are searched from the Chinese Complete Newspaper Database (CCND) by the theme words "Canton Fair" (CF, 广交会), referring to the records of its news reports in newspapers between May 5, 2000 and May 30, 2011. The number of records in total is 4333.
The findings are as follows. (1) Temporal distribution: The number (N) of the news increased year by year at first and reached the peak in 2006, and then began to decrease. The news reports concentrated in April and October every year. During the fair, the number of news reports of every CF's session decreased from the first phase to the third one. And the interannual change shows an annual periodic duplication by the number of news reports during the three phases. (2) Spatial distribution: The number (N) of news reports about CF and its Hartley of a given region/city are introduced into the CF's III on this region/city. The results show that the newspaper publishing companies are mainly located in Beijing, Shanghai and Guangzhou, and that the local/regional ones are concentrated in the east coastal provinces: Guangdong, Zhejiang, Jiangsu and Fujian. The city's III decreases from east to west. This result is similar to the exhibitors' spatial distribution of the 109th Canton Fair. (3) There are some relationships between economic development and distance with the III's spatial distribution reflected by correlation analysis. But Beijing and Shanghai do not obey the distance decay rule. For these two cities, distance is not an important factor affecting the spatial distribution of their IIIs. It is also found that the distance decay rule does not work at a short range within its host province, whilst it works very well beyond certain distance within all the cities except Beijing and Shanghai.
This study employs the perspective of media, as the media management is by all means a critical consideration of the event organizers. But nowadays with the acceleration of the information transition the media management may be unable to control the spatial distribution of impacts. This viewpoint needs more researches in the future. In addition, the intrinsic factors, such as operation, and extrinsic factors, such as economic structure and information technology development, have significant influence on the impacts of the events. The relationship between these factors is worthy of further study.

Key words: China Import and Export Fair (Canton Fair), mega-event, newspaper media, spatial-temporal distribution, Content Analysis Method (CAM), integrated impact index (III), information entropy (Hartley)