关键词: 网络通信系统，信息脆性风险，脆性环境，信息剩余度，极限嫡

Abstract: From system brittleness research point of view, this paper defined all the factors and incidents in a system,which can influence the system and arouse the system brittleness, as brittleness environment These factors and incidents can cause sudden collapse of the system. Based on the brittleness of the system environment, the paper established the network communication system brittleness structure model. Combined with brittleness entropy, process of information brittleness risk in a network information system was analyzed. The result of the analysis shows the practicable of the method. The effectiveness and stability of the system information brittleness structure analysis method were proved in the paper. In the end, through building analysis model of main brittleness factor, the paper applied the analysis method to a specific network information system, and obtained satisfactory results.

Key words: Network communication system, Information brittleness risk, Brittleness environment, Information surplus degree, Limit entropy