Abstract: Taking the IAAF Gold Label Road Race events in 2017(China)as examples, the study used the methods of spatial autocorrelation, distance cumulative curve, information diffusion radius to explore the spacetime law and mechanism of information diffusion in the network of major sports events.The results showed that the lifecycle of network information diffusion presented six stages, including Incubation period, Growth period, Repeatedly period, Outbreak period, Decline period and Stable period.The six stages showed the characteristics of long-term fluctuations before the events and the sudden drop in consistency after the events. Further, the amount of network information spread before the event was greater than after events. The spread of network information space revealed the trends of obvious economic and population concentration, and also illustrated the distance decay.Especially, the amount of information disseminated in the host area and surrounding areas were higher than that in the remote areas, reflecting the obvious local concentration. Finally, it is believed that event attraction, spatial distance, information level, economic development level, population size and social environment constituted the operational mechanism of the network information diffusion in major sports events.